I agree, the 'heat management' aspect is likely a prominent factor. Of course, I think many of us Prodigy users are probably doing mouth inhales, as direct hits at 5 volts are a *bit* much.
I run an 801 on my Prodigy, and I really do prefer it over the 901. The 901 gets hot a lot faster for obvious reasons, and the 801 allows me to dump
juice onto it in much greater quantities. I also prefer the flavor of the 801 at 5 volts. Give one a shot, but be really selective when choosing the specific manufacturer. After tons of testing and lost of money wasted, I stand behind the BE112 from Bestecig as my 801 of choice. Many of the other 801 atty options (if not all of them) have bridge / wicking / flooding issues that can totally ruin the experience.
My next experiment is to see if I can get an 801 cartridge to wick well with a shredded Pyramid Tea Bag (or two). If I can pull this off with success, my 'on the go' solution will be fully locked down. ;-)