It can play doom 3 and hl2 at full settings. I'm not that big of a gamer, I dont even have either of the previously mentioned games.
I seriously doubt that, unless you're playing at very low resolution, like I said. But how you know that without owning them, I don't know.
I guess I'm missing the point to this thread though, since you already seem to have an idea of what this card can do. But like I said, it's a budget card so it won't be great in newer games unless you play them at low resolutions or low settings. The 6600GT is more of the middle low end card, the 6600 really isn't a gaming card. Read
this review, it's for the X800 but contains benchmarks for the 6600GT and a few other cards. The 6600 isn't even shown there, but performs worse than the 6600GT, so you can kind of gauge how it will perform given similar settings and resolutions. I'd say the 6600 performs a good bit slower than the X700 in those reviews.