I know it's late now but I want to share my expirience with both cards,
Without debating with anyone here, when FS9 first came out I had an Nvidia ti 4200 64mb ram. I thought it was performing low and went to a local store and bought an XFX 5600 with 128mb of ram.
I took the XFX FX 5600 back about an hour after trying it because its performance was lower than that of the 4200.
I have an ATI 9200 non-se and is still slower than that ti 4200 it's just that the other components in my pc are fast enough that make up for it to where I can get decent performance when I'm away from big airports.