It all depends on what resolution your display is. And what your threshold is for 'great'. I put one in a budget build awhile back. It was paired with an Athlon II X4 and ran most games at pretty good frame rates at 1680x1050. But when I ran a more demanding game (DE:HR), it choked. I had to back off to a lower rez and drop some eye candy. But for the price, it's not bad.
its not bad, its just plaged with cards that are better choice then them. for instance, the HD 7750 is a bit weaker then the 550ti, but look at its advantages, extremely low power consumption, newer technology and requires no 6 pin connector. the you look slightly above the 550ti and you have the Gtx 460, 560SE, HD 7770 and HD 6850 which has a decently sized performance gap compared to the 550ti at a low cost. What plagues the 550ti is that people with oem psus cannot handle it as well(and result to the 7750) and people who DO have money buy a psu and the strongest GPU they can afford, and goes past the 550ti as the 550ti is the first 6 pin required gpu along with the 6750/6770 so they start to fade out.
The card is pretty good for a resolution like 720p. I've got a GTS450, and it's not too far down from a GTX550Ti, and it does offer good performance at 1280X720 or for your case 1280X1024. I wouldn't suggest this card for 1080p or so, cause I'm quite sure it will struggle even at low settings for most games.