I also gave up on technical preview on my 1020, and soon, will go back to win8.1 for my laptop as well. Although my experience wasn't as bad as yours, but I understand the frustration. People will say you were given warnings, disclaimers etc., I was fine with the rough experience, but with the new builds (desktop) ones, my laptop just started misbehaving, sound problems, cortana, start screen not opening, Critical shell errors, so on. If I experienced these on older builds, I would have accepted, but considering the fact that they are going to hit RTM next month, and saying newer build will bring stability, I doubt this has ever happened with me.
Installed 10130, rolled back in a few minutes to 10122. Jagged Experience. Also I feel like the feedback is not taken as it should be. Yes, the feedback with most up-votes deserves much attention, but for unique or rather rare system types, the errors faced won't be solved if this method was to be considered. My Hp laptop with beats audio hasn't been working properly since the very first build. Microphone issues and all, which were related to my PC (as I searched, but not the driver issues ), but should it mean I don't deserve the fixes.
For the phone, I was hell bent that I wouldn't go back to 8.1, even with delayed start screen , broken cortana with speech issues, I was ready to work it out, but all of a sudden phone started interfering with phone calls, messages, in general every thing went ****.
Yes there are people who have joined the TP program solely for testing purposes, there are some like me, who like to get things first, experience it and enjoy it keeping some kinks in the mind. But usability went aw.