Optical Switches utilize infrared sensors to actuate switches. Think of the safety sensor that stops a garage door from closing if you block it's signal. These switches act in a very similar manner, and are said to have far less input lag than the traditional mechanical switch. I have tried the Bloody keyboards listed below, and I personally cannot tell much difference, but that's because we're talking milliseconds here, so it's not super easy to pick up on even though it's there. Whether the difference is worthwhile is only for you to decide though, and I will mention here that none of these boards are the best "bang for your buck", since you're paying mostly for the optical switch technology.
Disclaimer: I have been sent the current Bloody keyboards for review.
Price: $140
Manufacturer: Bloody Gaming
Model: B930
Switches: "Light-Strike" Optical Switches (linear or clicky variants)
Keycaps: Laser-Etched ABS
Case Material: Plastic, aluminum plate
Backlighting/RGB: RGB
Detachable Cable: No
Other Notes: The point of this keyboard and the other current models (B975 and B945) is to almost entirely eliminate input lag. These keyboards utilize optical switches which do in fact eliminate input lag compared to standard metal contact mechanical switches, but although the difference is fairly substantial looking at response times, it's not a difference that is easily noticed. Along with using optical switches, the actuation distance on the keys is shorter than on other mechanical keyboards, which also technically benefits "input lag" but only because it actuates the key sooner within the keypress. I'll leave it to you to decide if the difference is worthwhile, technically it could give you an advantage in competitive gameplay, but personally it seems to be mostly placebo. This keyboard is designed for gamers, and that's apparent aesthetically as well. I suggest if you are looking at purchasing this keyboard, consider the B975 instead. The B975 has superior keycaps (Double-Shot ABS rather than Laser-Etched) and the overall build quality is superior. At this price point, you're really paying for the optical switch technology more than anything, so know that other keyboards at this price will likely be preferable in most areas. Note: The B945 model is very similar to the B930, except that it has a numpad on the left side. I will say though, there's nothing wrong with the build quality on this keyboard. It's certainly not perfect, but it isn't going to just break, I would argue it can probably take a few falls even.
Due to the shape of the keyboard, it cannot be paired with a wrist rest easily, at least not very many of them. If that's a concern you could look at the other models as the B975 and B945 both come with wrist rests. If the reason you're looking for a TKL (tenkeyless) board is that you want your hands closer together for ergonomics, the B945 is a fairly solid option as it succeeds in doing this while keeping the numpad, it's just placed on the left instead of the right side of the board.
Price: $140
Manufacturer: Wooting
Model: One
Switches: Flaretech Prism Switches (Linear or Clicky)
Keycaps: Laser-Etched ABS
Case Material: Plastic? aluminum plate
Backlighting/RGB: RGB
Detachable Cable: Yes
Other Notes: The Wooting One is similar to the Bloody keyboards, except it's switches have an analog function. The switches utilize sensors to not only determine if the switch is actuated, but also so determine how far the key is pressed down. This functionality could be useful for some applications, but not all. For instance, many videogames do not support this function. The keyboard overall seems fairly solid, but I would bet that it's fairly similar in build quality to the Bloody boards, although I have not personally used this keyboard and I have used the Bloody boards.
Price: $150
Manufacturer: Bloody Gaming
Model: B945
Switches: "Light-Strike" Optical Switches (linear or clicky variants)
Keycaps: Laser-Etched ABS
Case Material: Plastic, aluminum plate
Backlighting/RGB: RGB
Detachable Cable: No
Other Notes: The point of this keyboard and the other current models (B975 and B930) is to almost entirely eliminate input lag. These keyboards utilize optical switches which do in fact eliminate input lag compared to standard metal contact mechanical switches, but although the difference is fairly substantial looking at response times, it's not a difference that is easily noticed. Along with using optical switches, the actuation distance on the keys is shorter than on other mechanical keyboards, which also technically benefits "input lag" but only because it actuates the key sooner within the keypress. I'll leave it to you to decide if the difference is worthwhile, technically it could give you an advantage in competitive gameplay, but personally it seems to be mostly placebo. This keyboard is designed for gamers, and that's apparent aesthetically as well. I suggest if you are looking at purchasing this keyboard, consider the B975 instead. The B975 has superior keycaps (Double-Shot ABS rather than Laser-Etched) and the overall build quality is superior. At this price point, you're really paying for the optical switch technology more than anything, so know that other keyboards at this price will likely be preferable in most areas. Note: The B945 model is very similar to the B930, except that it has a numpad on the left side.
I love that the numpad is on the left side of this keyboard. Ergonomically it just makes sense. The whole idea of TKL (tenkeyless) boards is to move your hands closer together, and this succeeds to do that but retains it's numpad as well. I will say I prefer the build quality of the B975 over this model, it's just more up to date, but if the numpad functionality is important to you, and you want a more ergonomic option, there isn't a big enough difference to justify the B975 over this board in my opinion.
Price: $150
Manufacturer: Bloody Gaming
Model: B975
Switches: "Light-Strike" Optical Switches (linear or clicky variants)
Keycaps: Double-Shot ABS
Case Material: Plastic, aluminum plate
Backlighting/RGB: RGB
Detachable Cable: No
Other Notes: The point of this keyboard and the other current models (B930 and B945) is to almost entirely eliminate input lag. These keyboards utilize optical switches which do in fact eliminate input lag compared to standard metal contact mechanical switches, but although the difference is fairly substantial looking at response times, it's not a difference that is easily noticed. Along with using optical switches, the actuation distance on the keys is shorter than on other mechanical keyboards, which also technically benefits "input lag" but only because it actuates the key sooner within the keypress. I'll leave it to you to decide if the difference is worthwhile, technically it could give you an advantage in competitive gameplay, but personally it seems to be mostly placebo. This keyboard is designed for gamers, and that's apparent aesthetically as well. I suggest if you are looking at purchasing one of the bloody line of keyboards, consider the B975. The B975 has superior keycaps (Double-Shot ABS rather than Laser-Etched) and the overall build quality is superior. At this price point, you're really paying for the optical switch technology more than anything, so know that other keyboards at this price will likely be preferable in most areas. Note: The B945 model is very similar to the B930, except that it has a numpad on the left side.
The thing I love about the B975 over the B945 and the B930 isn't actually the keycaps, and I figure that might surprise some of you. The keycaps are definitely a significant upgrade, albeit they remain ABS, but the biggest difference for me is the switch wobble. Now it may just be a difference in tolerances of the other boards PCBs, I don't know, but the B975 definitely has less switch wobble than the B945 and the B930. And yes, I'm saying switch wobble, not stem. Because the switches are hot-swappable (the switches can be changed out without desoldering and soldering), they aren't as solid as I would like. The B975 addresses this issue though, and I would argue that there is very very little wobble with the whole switches, just some wobble from the stems like you would have with any mechanical board.