Things done wrong:
- Beta schedule was too tight for the clinical, gradual introduction of phased elements. Rejecting balance input in Beta 1 or 2 as "Beta 3 is when we will talk about balance" only works if Beta 3 is, indeed, about balance...as it was Beta 3 was about balance for about 2 weeks and then oops! Private Gamma!
It seemed like the devs would work on something behind the scenes in preparation for the appropriately scheduled phase and then if it didn't work immediately when brought in there would be no time to fix it. Unless you are looking at a 9-12 month beta cycle it's better just to put what you have out there at the beginning and make a controlled schedule on the dev side.
- The devs offered very little negative transparency. General dev posts are always good, and we got a lot of them. What we didn't get as much was a dev response to specific posts along the lines of "O yes, good idea, but we tried it out and it doesn't work." You had page after page of tester ranting that could have been instantly corked by someone briefly sketching where the devs had already been with regard to that particular subject.
- The Gamma at the beginning was held out as a carrot for the "best" testers. AFAIK no testers were invited into the Gamma. It's a status thing, but it also keeps the community invested. Reward your testers and do it publically.
- At times the devs seemed to ignore the testers on the most significant balance issues. We have been talking about broken stunlocking mechanics since beta 1. They never went away and that meant people stayed focused on them rather than finding the next exploitable mechanic. Anyone remember when flag locks were broken? They got fixed and we moved on. After six months of screaming we might have fixed stunlocking at release. But what did we miss meantime?
- Per below the small and committed test group is a good thing, but tends to stifle criticism. If the devs weigh in against a critic then they start to foster an Emperor's New Clothes culture. It's ok to be provocative but don't underestimate your influence.
Things done right:
- The posts detailing a specific aspect of developement like UI or AI were awesome and insightful. Having the developer responsible for that aspect talk about it was inspired. Similarly, getting general overviews from Frogboy was always good.
- Tester ideas are visible in many, many ways in the final product. In this sense the developers were very responsive to beta feedback.
- The developers were present in the forums and talked about their ideas and tester ideas. Really nice to see that, and I think it kept some tight mechanics in and some bad ones out.
- The pre-order Beta gives you a small, mature, and committed group of testers.
- Finally, you guys produced a good, good game 
It's really difficult to rate a Beta numerically so I'm going to use a few different indicators:
Intended: 9/10
Actual: 7/10
Compared to Industry Standard: 9/10
Combined: 8.3/10
Edit: after seeing the list of proposed day zero patch changes I feel bad about alot of the frustration I expressed above. Turns out you guys were listening the whole time. I'll leave it up as an indicator of tester feeling toward the end of the Beta process, but I'm upping my scores 