HH.357 seem like great atomizers, but didn't work out for me. I didn't get anywhere near the vapor production people on youtube were getting. I broke it in fine, and was using it on a good mod. It worked pretty well though, but crapped out after a month, not worth the price at all. If it lasted months then it'd be good. My dad also got one, but the longer barrel and it blew within a week.
I stick with cisco 306's now. Always great vapor production and good taste. The HH.357 tasted a bit better, but nothing to go crazy about.
I'd like to try the io6 next, but never going to buy an ava too expensive.