@DaveE: I did multiple test runs in raid and my observation is that sync works fine as long as people don't reset data once they entered the raid instance. If they don't I didn't see any issues with sync. If people have contrary observations, please describe specifically what the problem is.
Also invalid recount version syncs seem to be not accepted, as is intended.
If people do delete data mid-raid, yes there is a known issue and I'm working on it. It's tricky because I need to do surgery on the main data-structure again to fix it. But as said it's being worked on.
As far as I see it recount should work fine with sync in raid as long as people have the discipline of not deleting data during it.
I'll try telling the people in the raid not to reset once raid starts however I've seen the same problem when someone doesn't reset at all. A lot of people run recount and some of them forget to reset their data. The other day we did one pull on trash mobs in BT and someone ended up with some 90%+ of the dmg done after the sync doing more damage then the pull had total hitpoints. A possible work around to that is if a raidleader could force a clear on everyone in raid, unless I missed that option somewhere. Another issue could be if someone's client crashes and their data doesn't get saved, when they come back in they could have old data.