I agree with ChristianProgrammer...
This is really what it boils down to. This software is beta at MOST! I mean it says for testing purposes on the boot screen, so that's saying something. If you are not willing to break your phone, if you REALLY need your phone every day and this is your only means of communication, you should not be upgrading. Plain and simple. Some people want to roll the dice (I'm included) but this is about my 6th smart phone and I've been doing it for years. I'm no expert but I've done it enough that I can work my way through it. I'll be honest and say the internet's a little faster and yep...the GPS is working. BUT...if you're not a UPS delivery man in dire need of a GPS unit, you really can hold off until there's an official release.
On the other hand...I know you won't hold off
So I'll just say that throwing it on a FAT32 formatted SD card with the renamed file was about the easiest thing in the world. So if you are concerned do yourself a favor and wipe that snazzy 512 card that HTC was nice enough to give us and upgrade the heck out of it!