i just got my new iMac 27, coming from a mac pro 1,1. i have ZERO complaints. except maybe the price, but even then... I'm not too pissed about that either.
i like having easily accessible ports too, but i also feel like i take more pride in my workstation now that it looks so aesthetically pleasing. keep it cleaner, feel pressure to be more organized, etc.
in fact, i plan on mounting everything underneath my desk using that nifty pegboard mod. i'll probably add a card reader because I dont even use sd cards, i use cf 90% of the time.
the ONLY gripe i could possibly have, is it doesnt seem there is an easy way to use my BT keyboard and trackpad on multiple devices. i run my mac pro on monitors to the left and right of the imac and i dont like having two sets of input devices on my desk.
The Logitech solar-powered Mac keyboard would partially help there. It's not as nice as the Apple aluminum keyboard, but it has several BT buttons for switching between devices.