wow, so many helpful replies! hahaha thanks alot bros! yup, i am renting the 24-70 today for a trial, but the weather is not doing me any good. sigh. personally, i lean a little towards the 24-70. but, thats just after reading the reviews. i do agree that having the extra reach during holidays would be rather helpful, as i have experienced. weight-wise, i feel it SHOULD not be a problem as i've been working out very regularly. perhaps, going with the either, and a proper WA lens like 10-22 would totally replace my 17-85.
however, i am just a very normal photog. composition skills and such not that good. i feel getting such an expensive lens wont make it any better, albeit having better IQ.