It's hard to go wrong with any of the Sinar cameras, as long as you're not hiking with them. They're all well made and have tons of accessories. I'd let price and condition dictate my decision. I don't think any of them offer something that makes them head and shoulders above the other for most people. The P series are a bit heavier, but the F series aren't exactly light either. The P series makes repeatability easier, but who shoots product photography with film these days? To me, the most important quality of a studio camera should be the ease of using precise movements, and that means finding one that doesn't have worn out locks or gears.