Got my MCU2 and FM/XM radio upgrade done on 11/19. All that I can say is WOW, what a difference. Was it worth the $3k price tag? I guess it depends on your financial situation. I don't have $$ coming out my ass, but I can afford it and pay my CC of in 2-3 months. So for me, I would say a resounding YES. The web browser is usable and the display overall is very fast. One thing that I really didn't think about was the Netflix, Hulu, Youtube and such. I figured without the upgrade I would just watch this stuff on my tablet, no big deal right? No, it is. Netflix combined with the Premium sound system is amazing!
It turns out that my MCU1 had issues. It wouldn't even complete the techs diagnostic tests. The web browser would not load anything. It took like 20 sec to change radio stations. Navigation loading was very slow. Sometimes just completely unresponsive. I'll pimp Tesla and see if they'll rebate some of the costs but I'm not holding my breath. The SC did document the problems.
So, I say do the upgrade. The $$ only hurts for awhile and you will have an interface that will bring a smile to your face.