According to some, 8 speeds have a reputation for being slightly more reliable, due to a slightly larger chain, and less sandwiched gears. Others claim that there's no difference. The only thing that's "lost" is the 9 speed will offer you an ever so slightly shorter "jump" between gear ratios (on account of theres more of them), making it possible to dial in that "sweet spot" for your conditions. In other words if an 8 speed and a nine speed span the same distance...say, 12-32, the 9 speed will have shorter jumps. However, for me personally, I've never been able to tell the difference...my wife's bike is 9, and mine is 8. If I were a racer I probably would be able to tell, but then I'd probably also be running 10 speed Dura Ace. Since I just commute, I find the gear that's about right.

Having a 12-32 would lose you some more "fine tuning", as the geometric differences between individual gears gets larger. However, having a largest rear chainring of 32 to pair with a small front chainring of 32 or 48 could be a valuable bailout if the back or the legs just...can't...push...any...more.

Not to be condescending if you already know this, but what those numbers mean is that the rear cassette spans from 12 (smallest) to 32 (largest), with 8 total speeds. (Or 9, if that's what you're looking at.) Big rear with small front (sts) equals more pedal spin per wheel revolution. Small rear with big front (again, sts) equals less pedal spin per wheel revolution. The front cranks on these bikes aren't TOO different from one another, so I'm leaving their numbers out of this paragraph.

A 12-26 is not a bad gearing either. You could ride it, and find some hills to see if you need the "bailout." My bike is a 12-32, but in my commute because of that I NEVER need my smallest front chainring. I keep this rather large rear cassette though because I'm planning a bike tour in the not too distant future, and you never know if the day will come when a really really steep climb/gale force winds/fatigue may finally require that last gearing option.

I hope that helped a little bit?

If you're gonna get flat bars, once you remove the carbon and go to a Sirrus sport, at nearly equal price I think I prefer that one over the FX. It's a little more of a "road bike", yet still not really aggressive at all. With the sole exception of the rear cassette gearing, it's practically my Fuji commuter (the one I later converted to drops at some expense) with the equipment on it. And while I can't vouch for that exact bike, and can vouch for the componentry. By the way, I still use those R-440 shifters on my drops...it took some aircraft aluminum techs a bit of work, but we made them fit!