Yeah, I do the same thing as bauks...I fill it up probably more full than they recommend. Usually gives me quite a few pulls before it's spent, def more than 5 min. The herb def gets pretty hot in there, but again that might depend on how long you have the batteries in for. You should see some condensation on the lid...but I suspect that's just water vapor, so you might not see any if your bud is really dry. I don't think my material "swirls" around when I inhale...but I haven't really looked at it since I got the hang of using it. I do give it a shake or two after each toke, but I'm not really sure that's even necessary. If you have a largish, dense piece of bud in there, you might want to remove it and break it up a little in between pulls...but if you're using a grinder beforehand, shaking it before each toke should be enough.
As far as flavor goes, I can't really compare since I don't have any other vaporizer. Honestly, I don't use the MFLB most of the time...really only when portability and/or stealth is important. I'll use a bong or pipe when I'm at home (and am looking into purchasing a decent tabletop vaporizer)...but when I'm out and about (or when the neighbors are out in their backyard), I'll whip out the MFLB and toke in absolute secrecy.