Ashby,
Since I am currently in the purchase process for a 2552, and have no prior experience with the PC units, I don't have much to offer based on personal experience.
I can say that after extensive review of the forum, assessment of the ride and handling from many owners seem to be overwhelmingly positive--especially on the 2552. Liquid springs are certainly catching on to some extent, since during my early August visit to the factory I saw several liquid spring chassis in the dozen or so units they had in production. Given the expense of the option, and the consistently good review of the performance of the standard suspension however, I did not elect to include the liquid springs on my order. Obviously the best evaluation would come from a test drive and your personal opinion.
I personally did not hesitate to option the 50-amp service with the second A/C (along with the insulated windows). Not only that, I spec'd both A/C units at 15000 BTUs. In southeast Oklahoma, we've just come out of a summer with quite a few days hitting 105 degrees with 112+ heat index. Found similar conditions in quick trips down into Texas, along the Gulf, and over in Arkansas. Those kind of conditions will absorb just about all the A/C you can throw at it to stay comfortable. Obviously I will travel in many areas where I won't need that capability, and I can certainly drop to one unit (or none) when not needed. I've been in circumstances with inadequate A/C, and things can get pretty miserable. I think you should consider your climate, and that of areas in which you expect to travel predominately in making your decision.
During my visit, I had a very frank discussion with Phoenix regarding pricing. The recent 15% price increase coupled with the discount reduction from MSRP from about 26% previously to the current 20%, really bumped the out-the-door price. Even so, my experience matched jatrax's, in that they are adamant that "the price is the price". I think they are sensitive to the fact that their pricing changes are a hurdle to some new customers, but they can't really back off of them now, and as they explained to me, if they ever start negotiating price with one customer it would be unfair to all the others and there would be no stopping point from then on. That being said, I believe they look for ways to mitigate the sting a little if they can--there may be an opportunity to provide some other consideration besides adjusting the price of the unit. Since you have a trade, that may provide a ready opportunity for that consideration to take place, but your purchase price of the new unit will likely be the advertised price after discount.
Hope that you're able to put together an ideal unit, and that the 2552 becomes your next Phoenix Cruiser!