Originally posted by: Eureka
Go with the cheaper one. Having the PSU at the bottom is overrated, while it does help with lowering the center of mass of your case, its not that great since the PSU is a major heat source, and since heat rises you'll be dumping all of that back into your case. Plus the CM has tool-less features (which stink but at least they're there). However both will be a headache for cable management (I don't see a stock way to route behind the motherboard tray).
You can't be more wrong then that.
PSUs are not a major heat source, they are probably one of the coolest components inside the case, since, like yh125d said, all the heat they generate they exhaust it really fast. These cases, with the PSU mounted at the bottom, are very helpful, exactly for the PSU, since it's now cooled by the cooler air that sits at the bottom of the case. When installed in the upper part of the case, the PSU uses the hottest air available, to cool itself down, which is really stressful for it, probably making it run less efficient and reducing its lifetime.
I don't know for the CM case, but Antec 300 has a special place where you can conceal your cables. So cable management is not a headache at all, for the Antec 300. Plus , it has more places to install fans and it's very, very well ventilated.
The only downside is the lack of an air filter on the 120 mm fan place on the side and the lack of any kind of soundproof materials.
The tool-less feature seems to me that it's blow out of proportions, since what's the big deal if you use a screwdriver when you install your hard drive, or you use a manual plastic clip? It's not like you are going to install hard drives every 10 minutes or so, every day in your case. You put it there for months, or even years and you don't care if it lasts 2 minutes more to install it. So tool-less is a non feature, at least for me. It doesn't matter