The P180, although an incredible case, is far from perfect.
On the plus side, it's about as silent as it gets. Thanks to its triple-layer panels, everything's much quieter and many people have assembled systems that are effectively silent. It's got very soft rubber grommets for the hard drives to keep them from shaking and rattling around. It's also got an advantage in cooling thanks to its unique design where the PSU and hard drives are placed below everything else to keep their heat from getting to the motherboard and everything on it. It has a rear exhaust and a top exhaust fan, both 120mm, and a front spot for a 120mm intake fan so there's room for some good airflow in there for sure. In the bottom, there's a nice 38mm thick 120mm fan to pull in air from the bottom to cool the hard drives and PSU. And although many people choose to simply remove it rather than fool around with it, there's a VGA duct in the back that's supposed to be used to cool the PCI area (I, for one, refuse to believe that it's completely useless, people just give up too easily). So, to summarize it, it's #1 in silence and definitely "up there" in cooling. It's not the best in cooling due to its total lack of side ventilation whatsoever, but it's definitely up there thanks to its thermal isolation and exhaust power.
On the negative side, there have been multiple instances of people reporting that the door for their P180s bends and warps. Without going into too much detail, it suffices to say that the door tends to warp because of the material being altered by temperature changes. People have also reported many instances of the side panels' plastic clips busting because, well...they're plastic. From what I can gather, you have to be very careful when handling the P180's side doors if you don't want their clips to bust. Still others have said that the case's hard drive cages can get jammed in place - again, because plastic components are involved (why Antec used so much plastic in a case like the P180 I'll never know). Another common complaint is that the VGA/PCI cooling capabilities of the P180 tend to be very poor since the VGA duct is so hard to use. Silent PC Review's own look at the P180 showed that the budget-minded Antec SLK-3000b handily defeated the P180 in VGA cooling ability thanks to its side ventilation. I wouldn't even think about using an SLI setup in a P180 for this reason.
With the P180's VGA duct, you pretty much have to use a 15mm thick 80mm fan in it due to VGA card clearance issues, although I saw someone on HardOCP mod the duct to fit a 120mm fan (but I don't know what kind of a temperature effect that had). The PSU blows out hot air from the bottom, which rises and is most likely sucked in by the VGA duct, which could be one explanation for why so many people have hotter-than-average graphics cards. One reason I'm considering selling my P180 is because I'm worried about the VGA cooling capabilities of the case...take that opinion for what it's worth.
I've been looking at Cooler Master's new Ammo 533 case. Say what you will about its looks, but that ventilation on the side could provide some incredible circulation within the case. Just screw on a Sunbeam Wherever PCI Rack over the VGA card, put on one or two 120mm fans on the rack, blowing directly over the VGA and PCI area, and presto - thanks to the side ventilation, plenty of circulation that'll keep that area nice and cool.
So, no, the P180 is definitely NOT a perfect case. It's without a doubt one of the best to hit the market in some time, but it's not without its drawbacks either.