I'm someone with a 50+ game collection, and someone in my family is closer to the 170~ mark. that's a big reason behind my personal desire for the AVS, especially considering my NES at this point needs maintenance and I don't really have a proper upscaler any more and the last tube TV in the house is this tiny little thing we take camping.
Ideally, I'd love to own a XRGB Framemeister, but not only does the device itself cost around $400, but then you're also having SCART cables sent to you from the UK, you're having to make sure you have SCART to RGB20 adaptors, and in the NES's case, you actually need to have the console modded to output in RGB to get the same sort of picture quality out of it you'd get out of the AVS. at this point, we're at like... $550 if we were just setting up for doing this with our NES? and that's not even accounting for potential import gaming.
I'd mainly want a framemeister for all my other stuff, butt I'm not ready to take that plunge, and even then, the AVS is a far more portable solution for taking to a friend's house or such.