As @olotti mentioned you'd have the option of pressure transferring, not fermenting under pressure.I don't know what advantage pressure fermenting imparts. I have had very few problems with O2. I drink my beer fast so...
Which one?This one is cool, too - another in a series of these pressure capable, plastic fermenters with ball lock compatible hardware.
I still wish these fermenters had bottom draining spigots, though. It would be the best of both worlds. You could ferment without the need to force the beer up and out of the top, which either requires pressure or outboard CO2.
I installed a ball valve in a corny keg just for this purpose, but it would be nice to have simple plastic options, too.