The better console for value.

[NJ5]

The Cell in the PS3 is fundamentally much more powerful

No, it's not. It's much more powerful for certain applications (for example, embarassingly parallel problems which games are not). It's less powerful or equally powerful for some other applications (for example, an application which can't take advantage of more than two threads and which needs double-precision floating-point arithmetic; the Xenon would beat it there).

As for games (which should be our only concern here), the Cell is yet to be proven to be significantly more powerful. Then there are of course the PS3's other elements which can't be ignored (RAM size, GPU, etc.). The bottom line is that an absolute proof of the PS3's power must come in the form of a fantastically advanced game. While I don't think we've yet seen PS3's power peak, I don't think we'll see fantastic advances (even if we do it will be in very few games).

If the Cell was fundamentally more powerful, it would be significantly better for every single problem you could throw at it. At least that's my notion of "fundamentally more powerful". This is clearly and provably not the case due to defining properties of the Cell's architecture.

PS: There are also other desired attributes besides power as you know, but I'll leave that alone now.