The 610 runs wide, but this only effects its width.
Go true to size. (ie. I am a true size 9.5, so I buy my 610s in a size 9.5)
For those with normal or narrow width feet, the 610 may feel a bit wide on feet. I still recommend going TTS for normal/narrow width feet. For those with wider feet, the 610 will fit perfect.
Comfort Factor Ratings:
Cushioning (Softness): 6/10
Stability (Firmness): 6/10
Cushioning to Stability Ratio: 6:6
Midsole Shape (Foot support): 6/10
The 610 has a good combo of firmness and softness and the midsole is relatively supportive, but it lacks arch support. It's pretty comfortable for a regular lifestyle shoe.