I’m on Firefox 17 and using googlebot 2.1 (any googlebot works for me)… and the whole thing is working perfectly (inc Youtbe) with the added bonus of desktop view.
http://www.erikswan.net/browser_and_os/ gives me unidentified browser and OS, but advanced details show googlebot - I don’t know whether the Network could pick up on that suspicious googlebot thing, but so far so good.
My device is 2.3, routed and I'm using stock tether. I've come around to User Agent Switcher after spending weeks concentrating on apps that supposedly hide tether usage - they don't, not any more. PdaNet lasted only 10min (7MB download) before my Network discovered I was tethering. Orbot was a little better - 500MB before I was caught out again. So much focus has been on apps to do the job – and now they’re easily discovered by Networks, User Agent Switcher seems to have slipped under the radar.
And if you're going to download Youtube vids just do it on your mobile.