I’d hold off and see how this X2 product plays out at NAB. It’s their new capture card and has built in support for HD and HDV along with all the features of the RTX100. If it does what it promises for a cost effective solution, it’d be worth holding off a few months till reviews come out for it.
Avid’s not really a prudent solution. I’ve yet to see an Avid that rendered quickly. Avid gets by a lot on name alone, IMO. I think their editing is perfect for filmmakers that edited film and are going digital. But for a new user, you’ll be confounded for a good long while, and you’ll find your skill set doesn’t apply directly to any other editing software (which is fine for some, since most Avid users tend to be very insular about their purchase)
All said and done, I like my RTX100. I don’t have the cash, nor the business to do upgrades like crazy, so as much as I’d like a dual AMD system, it ain’t happening anytime soon. I also like having the WYSIWYG output and the realtime MPEG2 rendering is nice too, for my system’s specs are about 2 years old.