When I first got my current bike, it would bother my back a bit when I rode it, but after a few days that was okay. Then it would bother my back a bit if I rode in the drops, but I sort of got used to that and it was okay. If I'm off the bike for two or three days or don't ride in the drops any for a while, I'll notice it when I get back on. Basically, if you're in any position that you're not normally in, it may bother you.
__________________
"be careful this rando stuff is addictive and dan's the 'pusher'."