Well just to be different, my experiences.
1. Start menu seems just fine to me. Yes, it could do with a couple of tweaks, but the general idea seems very good. If you're surprised it needs a few small changes - hello, it's a technical preview. If you're expecting software which needs no improvements or changes, why install software labelled as technical preview?
2. Performance seems pretty good, no crashes yet. IE in particular seems to have gotten quite a bit faster - definitely looking forward to Spartan.
3. With about 5 minutes of work, not needing google - Cortana up and working fine, not hard at all - seriously, take 5 minutes and get it working before complaining about it not working!