SFX form factor is a PITA. For starters, there are at least three different physical sizes. Secondly, efficiency is below equivalent ATX power supplies (AFAIR). Thirdly, 300W versions are rare - most are around 200W or so.
I have absolutely no idea what posessed Antec to use an SFX PS in the 3300 case: they were cheap because no-one wanted them? Outside the US, Antec has been selling the
3400, which uses a
standard 380W ATX power supply. Perhaps that's the version that Merc has used?
The separate chamber makes no sense in the 3300, unless you're assuming that the airflow through the PS is too low to cool anything other than itself, and you're going to fit a far stronger fan to cool everything else. That's a shitty design.
There's a shitty review to match on SPCR. It's the worst review I've read in ages (but then, I try to avoid reading them) and has really made me question their value as a review site. I was going to post a full critique, but shook myself out of it (got a life).
Anyway, the 3400 should be acceptable if the price is right. Alternatively, there's equivalent solutions from lots of manufacturers, including the
ECE3275 from Ever Case (includes near-silent 300W PS with 12cm fan from FSP), the
TJ08 from Silverstone, Coolermaster, HEC, etc.
I wouldn't recommend a high-powered graphics setup in a mATX case unless it's
truly well designed like the TJ08 (pity the front ports are so low).
Oh yeah, here's a tip. Modern ATX power supplies are explicitly designed to extract hot air directly above the CPU and graphics card. This isn't going to work so well if you leave the rear case fan unblocked, so seal it off if you're not using it.
Secondly, don't use the rear fan unless you're going to push a decent amount of air through the front as well.
Thirdly, don't push a decent amount of air through the front unless you have a bad-ass graphics setup - a trickle to create some air movement in the vicinity of the hard drive and hopefully the graphics/motherboard chipsets is enough. For most systems, don't use a front fan at all - the CPU ducting present on most cases flows more than enough already.
You have to avoid wildly mismatched flows or you'll start to go backwards (and even shorten the life of components such as the power supply). View all the vents and fans as a system rather than discrete components. Remember that air only moves near a region of high or low pressure, and that blowing is not the same as sucking when it comes to localization of that pressure differential.
Oh yeah, and airflow doesn't go around corners.
Anyway, that's the results of more than a decade of experiments attempting to manage heat and noise in PCs. Hope it helps someone.