I own two 2.5 and tomorrow I'll have my P3. The menu sure has changed but the fact is still they both put out exact voltage every time. The dinosaur 2.5 works like a charm. At least if it needs repairs Provape will repair them.
If you feel the 2.5 works as well as the P3 then why buy a P3? Since you seem to believe the 2.5 is perfect and all you'll ever need why spend the $$$ to get a P3? Surely you don't see anything lacking in the 2.5. That would be provari heresy!