stocks feel much nicer!! mods feel like kids bikes, small, twichy, nasty!! Stocks actually seem to fit grown people, the bikes are more stable and can roll over a lot more stuff. I would say the handling was a bit more nimble on a stock. With a mod, you have a really long boat of a stem, so steering feels really naff! On a stock the steering and handling is much nicer (unless you have a big high bb frame!)