I have had Petes, but the 1970's Savinelli System appealed to me more. I have two straights and two bents. They are almost exactly the same as the Pete System. My problem is that you have to be aware that the pipe is designed to work best held upright, because of gravity drawing the moisture down into the reservoir. But, then you've got this little bit of nasty and vile smelling liquid in your pipe. So, if you lay your pipe down sideways while smoking or afterwards, you get that crap poured through the nasty chamber and into your pocket, or dampening the tobacco your smoking with putrid spunk. It's never very much liquid, but like skunk spray, it doesn't take much to ruin a shirt or a smoke.
I think that the key is always making sure you have a stand to hold your pipe when you have to put it down. It's not very practical, IMO. Besides, they don't magically make a smoke better, unless you just haven't developed a preference for drying your tobacco and smoking in a slow, sipping manner. They would probably work best for the "straight of the tin" and puff like choo choo folks.
I do smoke my Bent Dublin Savinelli Dry quite a bit, but it is dedicated to aromatics and I shove a small piece of cotton in the dry well, and I remove it after the smoke. I've noticed that smokingpipes has announced that Savinelli is reviving that line of dry system pipes again. They are sweet looking pipes.