After over 2 years with an ATI 4870 it was beginning to show some slowdown with some titles at 1080p resolution.
Given a low end AMD Athlon 6000 system, 400w power supply, and little space in a small form factor case, upgrade paths were getting narrower.
I tried a Palit GTX 460 which ended up being a defective sample, but was around 10% faster than the ATI 4870 at the standard SVGA resolutions with benchmarking tools, before the blue screens started.
I settled on this Gigabyte GTX 560 model, being around 10% factory overclocked from the standard 822Mhz, given that the SOC 1GHz Gigabyte model was in low supply in the UK at the time, commanding a 20-30% premium over lower models and having higher power requirements.
Benefits of this GTX 560 in my case were the smaller size over the ATI 4870 (though not as compact as the GTX 460), quieter fans - the Gigabyte 'Windforce' cooler angles the fans to reduce turbulence, in theory allowing air to exhaust faster, and lower ambient temps - the PC no longer keeps my feet as warm and the cat prefers to sleep elsewhere. The CUDA implementation for the GeForce series was also of interest, since the developer resources seem to be more accessible and more mature than the equivalent ATI stream API - it remains to be seen when (if) the Open CL libraries become the standard.
The box contained driver disk, DSUB-DVI converter, two Molex to PCI converters and the card, so a no frills package.
Running the standard free 3DMark tests were artificial, as they restrict the resolution of the test, so the 20% or so increase over the old 4870 was relatively useless.
I figured the best way to test it was to up the details and settings and see if the stutters went away, and as far as the titles I've tried go, it's a success. Assassin's Creed 2 and Prince of Persia (bespoke engine), FEAR 2 (Lithtech) and DIRT 2 were all fine (Added: Resident Evil 5 at 1900x1200/NoAA runs at over 50fps).
For those with a similar/old systems, it's a good upgrade for an old card - if you want to run high resolutions, and need to scratch that itch. Anything more powerful is likely to be hindered by the CPU, and those running 2560x1600 monitors are going to need to spend much more to get the grunt to drive them, so it's probably the end of the line for my little box. Just don't forget to vacuum out the dust (I used a Giotto Rocket air blower recently) when you upgrade...