I just recently picked up a 801 penstyle. I like the size, love the cart capacity, but the 801 has no "gumption".....
I need a recommendation on a penstyle atty that is compatible with the 801
threads (or are they all?) and performs (TH and flavor wise) like a 901.
It could be the atty that's giving you problems, or the battery. I have (almost) all the penstyle models, and have different problems with each

Also, if the atty is flooded, it will fizzle, and if the battery is getting low, it blows. So basically it could be either.
As far as compatibility, they all pretty much work together. I prefer my 801 attys (now that I've had THREE 302 Joye attys and one BE112 die in the last week, all because of dark liquids) The ones that seem to work best together tho, are the Joye 302 and the SLB 801. My M201 will only work with itself, and the BE112 works okay with the others, but something just doesn't feel "right".. if that makes any
sense.
I have finally decided I need to use my lighter fruity flavors on the Penstyles, and my darker flavors on my 510.
HTH!
BTW... ecigsupply was having a sale on 801 attys @ $5 a pop (plus a code for % off)