Spark 2.0 alternatives

Spark email V3 is a rewrite of IMO the best email client out there. I have been a user since V1 and have tried an compared many other email apps but for me Spark is head and shoulders above others in a crowded field. V3 is fast and the way it is organized I can get through hundreds of emails very quickly. I was on the beta testing group and while it is true that this release is not in parity with V2XXX, Spark developers are embarking on a new paradigm for email and I know for a fact that robust features and awesome UI will come in time. I am using both versions side by side and the feature to block or accept new senders is paying off for me in spades.