Originally Posted by
haxartus
Yes, significantly. 550ti is comparable to 5770 which is basically 4870 in performance, and you can see that 4670 is a few steps below 4870.
As for WoW, you can probably run it on High outside of raids, with shadows on low of course, because of the CPU. The only problem with the card it is that it's usually 1GB VRAM, which means you can forget about playing the new console ports that require 2 or 3GB VRAM. But you can't really ask much more form a £100 configuration, in fact it's amazing for that price.