I have never run any of the pre-2700 builds, so I cannot comment on their performance.
2708 runs great for me (as have 05,06 and 07).
If you don't want to run them, then stick to the releases.
If you aren't "missing" any of the function(s) added since 2600, then you probably can wait for them to go gold.
For me, one of the main draws (integrated inbox) was not introduced into the 25xx builds, so I never messed around with market builds.
The bug you refer to has to do with a specific mail server. I have not seen any similar issues with gmail IMAP idle.
If you run into bugs you can post them to the tracker; the devs are VG about responding/addressing to issues that are legit.