The X700 pro is roughly equivalent to the vanilla X1300.
I disagree, it's more like the inverse, the X700 vanilla is the equivalent of the X1300PRO;http://www.xbitlabs.com/articles/video/display/radeon-x1300.htmlhttp://www.xbitlabs.com/articles/video/display/xfx-gf6600-ddr2.html
If anything the X700Pro is closer to the vanilla X1600 IMO (the X1600XT clobers it though), but I do agree with where you put the GF6600GT for the X700P. But be sure to check the AA+AF rewsults, like in BF2 where the X700P outperforms the GF6600GT throughout the resolutions;http://www.xbitlabs.com/articles/video/display/radeon-x1600_3.html
And if you check further on in HL2 similar results where the lead shifts with AA+AF. However overall the GT will win.
Anywhoo I'd put it closest to a plain X1600 in the new generation, or more acurately somewhere between the X1300PRO and the plain X1600 but closer to the latter.