I tend to agree with Mach1219 on the PSU being mounted on the top as favorable. It's part of the dilemma I am having with upgrading from a mid tower(centurion from cooler master) to a full tower, because a lot of the good cases now have the PSU on the bottom. I actually have my case on top of a file cabinet which is the same height as my desk and alongside it.
I also like the fact that the cooler master centurion(case I own)has all of the usb ports front bottom mounted instead of the top, because then they're at desk height where it sits. I can plug my mp3 player in it and see what is going on without needing a big ol usb cord. I noticed a lot of these good cases also have their front ports top mounted now. So my guess is that a lot of these moves in the PSU and port location were due more to the fact that power users tend to have these heavy systems sitting on their floor so they needed a better airflow to more sensitive components like the mobo and cpu since there is a lack of air flow to being with in floor mounting. But I really worry that too much radiant heat will be coming up from that PSU to these components if it's bottom mounted and that the PSU can handle more heat then they can. I am not as experienced in this as others, so that is only my opinion.
On a side note I am wondering if it is really worth modding my case(I like to tinker) for more airflow (more holes more fans)and ramming a top notch video card in there(currently I have a geforce 7600) or springing for a new case. I notice slightly hot temps with only a good cpu cooler and extra side fan but if this can really be solved by cutting more holes and putting in more fans and a top notch vg card will stay cool in this mid tower then I want to do that. Can anyone share their experiences? It will be a tight but I as I stated before, I really like the setup of the case design(top mount psu bottom mounted front panel). Thanks.