As Viper said, ATI cards have very poor drivers' support. Performance is OK as long as drivers are working fine. Again, it's also the matter of preference. I have always been Intel's and nVidia's advocate since with AMD I have had only bad experience.
But again, the fact that this desktop is Dell outweighs one small minus called Radeon GPU...
Don't get too excited. "Ivy Bridge" CPUs have a small (5-10%) performance advantage over 2nd generation Sandy Bridge chips, also Ivy Bridge CPUs use less power and have a more powerful graphics chip built in; however you still can't compare Ivy i3 with Sandy i7. i7 still wins.
i3-2200 (Ivy) vs i7-2700K (Sandy) comparison.
btw, how well would they both run tf2?