Looking to replace the Bonneville with the Firebolt or City-X. have ridden the City but not the Firebolt....My two main concerns with the Bonneville are high freq vibe on highway and lack of grunt. Will these be concerns with a Firebolt or City-X?
I don't have any issues with either lack of "grunt" or buzzing on my Firebolt. In fact, I was riding with a buddy over the weekend while he was demo riding an SV650S, and we traded for a bit so I could try out the Suzuki. His first time on my Buell...his comments were "Man, that thing has a lot of power," and "It was far smoother than I expected." A lot of guys think that because Buells are paintshakers at idle, they'll vibrate you off the seat--but actually, the engine smooths out nicely by the time it hits 3K rpm (although you always know it's there...living, breathing, ready to go...).
For strictly commuting, I'd probably recommend the CityX. I quite like that bike (well, the Lightning XB9S which is very similar), but I bought a Firebolt because I mostly ride twisty mountain highways (I live in "ski country"). The bike I'd be most interested in at the minute would be a Super TT, or better yet a CityX modified with a Uly subframe and seat (yeah, I know it doesn't fit...).