Buckshot,

Whether or not the high-end of a previous generation will beat the low-end of the new generation is on a completely case-by-case basis. Take the highest end of Hyperthreaded Pentium CPUs versus the lowest end Core 2 CPUs. There are plenty of situations where the low end Core 2 will beat the high end Pentium. When the DX8 cards came out a low-end DX8 card would beat a high-end DX7 card almost every time. There isn't some phsyical law on generations that states they have to act in the manner you're describing.

And even if you buy all of that it's all predicated on the consumer knowing that the X700 and X1550 are of different "generations". They could easily be of the same generation with an entire array of X900s, X1000s, and X1200s in between, each gradually more powerful as the numbers seem to indicate. Somehow, you'd have to magically know that the 1 in X1550 was part of the X and not the 550. A google search for "Radeon X1 series" returns 1,710 results, none of which appear to point towards ATI's website, so I'm not even convinced there is an "X1 Generation".

For the average consumer, I don't see how this makes any sense. I'm fairly knowledgeable about this stuff and I still found it pretty confusing. The specas are about the only thing you've got. The X1550 is a higher clock speed GPU with faster RAM on a faster bus and more of it. Not to mention it was manufactured a couple of years after the release of the X600 so why should it only be slightly more powerful?