My favorite models to build are World War Two fighter planes, and perhaps the occasional jet fighter, so 1:48 is my personal favorite. The problem I have with 1:72 is that areas like the landing gear and cockpit are woefully under-detailed, often with just a seat and an instrument panel with no detailing. I suppose there are resin kits and the like to make up for this, but painting and glueing such small pieces would be beyond my abilities, and it would be difficult to actually see such intricate work if I could do it anyway.
With 1:32 scale airplanes, small problems such as wings not fitting into the fuselage or warpage is grossly amplified, and can really stand out as flaws that would be less noticeable in a 1:48 scale model. I would also have difficulty fitting such a large model on my shelf anyway.
With modern aircraft, which are really a lot bigger than WWII planes, I could see 1:72 scale--that would put an F-16 as being about as large as an ME-109 or something, and would keep the same compromise of detail/flaws relatively well. Something in between might be better...1:60 or something?
I haven't done modern planes in a while, and don't plan to...it's nice to have a large collection of the same era. And there are hundreds more WWII fighters that I have yet to build!