Hey Donraj86, beta 2.1 is way better than the latest 2.0 IMHO. It may be a little less stable but it's way faster. When I say it's a little less stable, I meant you may have to reboot once a month instead of once in 6 months, which I found it's no big deal for me.
Ubuntu? I don't know PB supports that. Are you sure?
Sideloading is easy, but I don't like the experience of sideloaded apps, you might be disappointed there too. But having Internet access anytime anywhere through your BB9900 might make it up for you.
Hope you enjoy your PB, and don't forget, you will be getting BB10 on your PB sometime next year, it's going to be great.