I've also had indexing issues with M2, but that really is the price to be paid for being on the bleeding edge. Lots of changes have occured on the backend which has led to greater performance but migrating from snapshots is not part of that focus. That said, although I get old feed items in new feed access points and I have lots of undeletable ghost mails in my trash, I don't have any major problems.
Quite a number of those unofficial bugs are not reproducible. Still a useful resource for beta testers.
As a sidenote, the weekly releases are *not* beta releases, they are snapshots (developer builds) - that means the QA on them is limited and they may well break things seriously; they do mention that. Backups of the mail store are thus always recommended so you can rollback if needed...