Late, I bought a 100SG, the one with the tiny colour cup, and a fine head last year for detail work, as I have an Omni4000 for area work.
However I now use the 100 for any work which requires a greater degree of control, ie soft edged camo, no matter how large. It's not that you can't acheive the results with the Omni, it's just that I have found the 100 easier to control.
As spraying problems with the fine head, I usually use Gunze acrylics thinned 50/50 with Tamiya thinner without issue. The only time I have encountered problems is with Lifecolour acrylics, but this was more due to my thinning ratios than any failing on the part of the AB.
In short go for the 100G or LG, you won't be disapointed.
Karl