from what i read, if you haven't tried to do anything physical to see yourself what happened to a dead hh.357, you can send it back to hanna and he can either try to fix it or send you a replacement. it's been said in a few reviews and threads but it's said so rarely you might have a hard time trying to find proof. i will trying to contact him about my dead hh.357 and see what goes on from there.
the i06 would be my 2nd choice; though i've not personally owned one i just judged for myself with the (at least) 30+ google searches i did comparing it to a 357. vapor's on par with the 357, but flavor is just a tad more "better" on the 357. at least that's what more then 2/3's of what the reviewer's said on videos and review threads. the other 1/3 couldn't tell the difference. take it with a grain of salt though, that's where my research brought me
either way, the man behind the 357 is a vote for me if your counting votes. he's even working on an atty-tank that won't just fit the 357, but fit any standard atty out there. i will be getting my forth hh.357 when that comes out, so it's something you may want to keep in mind if you come to love dripping but hate the tediousness that comes with it. i was purely a super-mega carto-guy (the giant dual coil clear carts) until i got a hold of a 357.
as for longevity, i can personally say that it's lasted a good 2 months before i crapped it out (my first one) my 2nd one is a long barrel 2.0 ohm that has lasted about 2 weeks (so far) and finally broke in to my comfort zone last night. If you do end up getting a 357, infact any of the higher top-notch atty's in the market, there is a break in period so don't get discouraged if your not liking it at first. just vape and vape and vape till it settles.
in comparison to my first ever atty which was a joy 510, it did last me a long time at only 5 dollars from my local merch before i decided i wanted to change flavors. mileage will vary with those though. I went through 3 in 2 weeks because the first one i got had vanilla extract juice in it i couldn't get out (which still works today but has been in my box of vape equipment), and the 2nd one was doa after a day. the third i got a few days before my hh came in the mail. been collecting dust since. i'm assuming it works... if it didn't dry out already.