it depends, what are you looking to compare between hits? potency and satisfaction, or efficiency/stealth?
In potency and satisfaction, the MFLB just cannot touch the PAX. Not one bit. Not with powerex batteries, not with the PA setup, nothing. It just does not compare, it is like racing an M3 with a toyota prius.
But the car comparison kind of holds apt imo, because efficiency/stealth is the only place the MFLB dominates. The only true one-hitter (as the heat up and cooldown times are near instant), with a smallish cloud you can control real well.
Taste wise? They're pretty similar - the PAX adds a tiny bit of mouthpiece air flavor, and the MFLB adds a tiny bit of wood flavor. They're both hardly perceptible.
But yes, if you'er looking for satisfaction.. the PAX is it. I found the MFLB frustrating (yes, even with PA), personally. If you've got a decent tolerance you'll need to carry around at least 3-4 batteries on the MFLB for a single session.