I don't think there is one "best" atty, only attys that are better suited for one situation or another. For me, the 510 is the best performing atty that I've tried, but it's sort of a hassle. A bit of leaking, not wicking (if not dripping), and constantly having to top off or drip makes it my "at home" atty. That said, it's a true vaper producing champ. Out and about, or when I want a strong flavor, or I just don't feel like refilling every 10 minutes, the 808's are my go to atty. I use both daily and would be very upset if I only had one or the other.
I've been using the 808's on my Tornado (with adapter) and it's nearly the perfect setup. The cone fits over the 808's, though it does have a pretty tight draw if you don't remove the sticker on the atty. Overall though, it's a great combo.