You do have to get accustomed to P-lips if you are more used to traditional bits, such as the fishtail. I'm not an expert on stomatitis, but based on what you posted, it seems to be caused by heat from excessive smoking. If that is the case, smoking more slowly and perhaps a little less seems to be the appropriate measure; if you smoke like a train, I don't think a different bit will help actually address the real issue.
As for P-lips, it took me time to come around to them. I never outright hated them, but they did feel awkward at first. But as I got used to them (and as my smoking technique improved) I found that I actually preferred them over fishtail bits. I like how they disperse the smoke, and I find I can now clench them more easily than fishtail bits. And I got a handful of great pipes from American artisans (e.g. Boswell, Tinsky, etc.), but my absolute best smokers are my Deluxe Systems.