MY first lathe was the Delta Midi, which is extremely similar to the Jet mini, and love it. I still use it often for a variety of tasks. Our club owns six of the Jet Minis (1 vs model) and everyone seems to agree that it was money well spent, but also understand that it does have size limitations. I started to really enjoy turning bowls and none of the minis/midis/etc. can really do much in that area. Too high of a starting speed and too little HP. So after looking around what was available on the market and what $$$ I had I purchased the Jet 1642 (3 hp I think, the bigger 220v VS model). Haven't regretted it a minute but I am also very glad that I started on something smaller and a little less itimidating. Never touched or actually seen a PSI except in catalogs, but you won't regret buying a Jet in my opinion.
Moving up to a bigger lathe is not as expensive as the first lathe was, all the turning tools and stuff like that was much more expensive than the actual lathe. So when I bought the new lathe I didn't need to upgrade my tools really, or the sharpening station, new insert made the chucks work on it, etc.