I decided I should re-post some of my group posts here:
When I first purchased my 718 I got a cheap MFJ-902 which worked very well but required retuning when changing bands. This wasn't really a problem but I felt I needed something quicker and slicker!
I then purchased the LDG-Z100, made a connecting cable and had some fun. It tuned quickly and did a good job but it wouldn't match my inverted L on 20m. I also got to wondering if it was actually optimally tuned for each band, as you can't 'twiddle' the knobs you are at the mercy of the tuner.
I then performed the Phil Silas mod on the MFJ-902 to add an absorbative SWR bridge (http://www.ad5x.com/images/Presentations/MFJ902RevA.pdf).
This made tuning the MFJ a dream, you can see the match being made, can twiddle the knobs to get that last ounce out of the tuner and it also matches my 20 m Inverted L so has a much wider matching range.
I have never used the LDG since. That is not to say I won't again I just don't see the need.
I would heartily recommend you go for a manual tuner, buy or make one. I am now getting the parts to make my own Z match (two variable caps 30 USD and a couple of coils of wire for one of the best ATUs ever invented, so I'm continuously told!). For 30 USD it's worth it.
So I have gone a strange route: manual, auto back to manual and I'll stay manual for as long as I can see.
If you want the LDG Z100, make me an offer!
The topic has gone onto aerials - well there are two things to do before you make any choices.
1. Buy any of Kurt N Sterba's Aerial books
2. Buy wire
We spend so much time wondering if we have got the best solution we miss the pleasure of just doing things. This is well known by the aerial manufacturers who fill the void by telling us their 1m high, no radials required, low SWR across the band antenna is the dog'g dangly bits that we gleefully take it all in and pay out hundreds of £s (or $s) to feel we got the best we could.
The reality is that a simple dipole will do wonders. Put up a doublet and use a balanced tuner (Z match, 30 USD) and you can get on all bands efficiently (in radio and dollar terms!).
Quite a lengthy response but hopefully a helpful one.
By all means get the LDG tuner (I did) but you may always wonder if you could get more out with a manual tuner you control and for a lot less outlay. Maybe we need to try both manual and auto before we make our minds up, which you try first is your decision.
Whatever it is it, have the antenna ready to hook it up and CQ DX!