I personally thing they are both rather poor and no real use for playing games - or not any of the newer ones anyway. Turbocache works by "borrowing" memory from the rest of the computer by the way. That means that whatever your computer has as its base memory you have to subtract the amount the graphics card uses. This might not be a problem if you have a large amount of memory but most PCs I have seen with Turbocache are budget systems with minimal memories and with the graphics "borrowing" the memory it makes them even slower.
It depends what you want the PC for. Both cards are poor. Depending on the spec of the PC one might be better than the other. Personally wouldn't have either of them as I play games.