After playing both basses back to back this week, the two are a toss up to me and I go back and forth on which I actually like better.
Overall, I really like the tone of the Sadowsky the best, but what bothers me about them is the lack of treble roll-off (I know, get one with a VTC, but it's still prefer to be able to cut) and the lack of a mid adjustment. I understand and respect Rogers' view on not having a pre with a mid control, but for me, I really love to play with the mids both cutting and boosting, so not having one on a bass is a serious drawback for me. I will say that the Sadowsky is the bass I like the best that doesn't have a mid control though.
I like the styling and the feel of the Fbass over the Sadowsky. The neck feels a bit better to me although I like them both, but when it's strapped, the Fbass is hands down more comfortable to play even though they are much heavier than the Sadowsky. The Fbass pre is a bit more user friendly for me, but I wish that it had a mid and treble cut rather than just a boost. The output is a bit on the low side too, and even though it's an easy fix, I really wish that the pickups were hotter.
As of right now, I've decided that if I want to go Ash/Maple, I prefer the Fbass, but if I wanted anything with a Rosewood board, I'd go with the Sadowsky even though you really can't go wrong with either choice.