Tell you what - I'll make you a great deal on my EP175 and then I can either save for a VTF-3R or a PB12-Plus. Or a EP500...mmmmmmmmmmm...
In all seriousness, the EP175 IS a very good sub. I suspect part of my complaints stem from the fact that it's right next to the couch, and even though it's callibrated properly for my listening position I can hear every last thing that's going on. Combine that with a fixed 100hz crossover on my Marantz, and the sub becomes a little too easy to localize.
Put it this way: If I bought my setup today, I'd probably look at one of the subs I mentioned above. On the other hand, I've lived with mine for two years now and I haven't felt compelled to spring for a different sub. It does its thing very, very well. Its "thing", however, just doesn't include the extension that other subs from HSU, SVS and Axiom might offer.