I've been lurking since ATS was announced, and am still waiting for a proper stable release. I work for an ISP, and would like to use ATS for various proxies and caches, but can't run an "unstable" release and I can't set up a new platform without IPv6 support. Therefore we're still rolling out squid and varnish proxies/caches where ATS might have been a better choice.
So please, if v2.1 really is (almost) as stable as v2.0 -- get a new stable release out ASAP, so that we can start seriously considering it. -jf