I have a P180. Loved it at first sight.
A few caveats, though.
A loaded P180 is heavy. Even empty, it's quite hefty.
Wire management will be challenging. That's a guarantee. If you're the type who likes to keep his wiring neat and tidy, the P180 is not a good case to work with. Aside from airflow control, though, the compulsion to make your cable management artful is largely an indulgence to vanity (something I indulge in, in fact).
As another respondent said, the exterior dimensions will fool you into thinking it's a big case inside. It's not. It's horribly cramped. This makes the case a bit tough to work in. However, on the plus side, the quality of manufacture is very good. You won't get wounded working inside a P180 (I've had a few nicks and cuts in other, inferior cases).
The front door contributes much to the clean, sleek aesthetic of the case, but it's also prone to warping. Mine warped several months after I bought it. I've read in several websites that this is a common issue with the P180, one that Antec supposedly addressed in a revised version of the model. However, even some of the revised examples had warping issues.
This warping issue drove me to get another case for myself. The P180 is now my dad's PC's home. The warping, strangely enough, seems to come and go, a phenomenon I simply cannot explain. I thought it might be a temperature-driven issue, but I'm not sure anymore.
Hope this helps!