PowerColor's HD 5750 Low Profile is the fastest low profile graphics card available today. This basically makes it a must if you are looking to build a high-performance 3D small form factor rig. While the card does not have enough power for all titles in full HD 1080p with maximum details, you may be able to run them at lower detail settings. Lower resolutions, including 720p HD will run fine though. In terms of power consumption the card is similar to the reference HD 5750 with 15W in idle and 26W in Blu-Ray. Fan noise in idle is excellent too, but in 3D the fan ramps up to emit a distinct noise. This is not a high-pitched whine some would expect from small-sized fans. Considering a load temperature of 75°C I think PowerColor did all they could to quieten the fan. Another interesting aspect of the card is its massive overclocking capability. In order to keep power and noise as low as possible, PowerColor decided to use AMD's reference clocks on their card. This results in excellent overclocking potential - up by 33% GPU clock and 13% memory clock. The resulting performance is similar to a HD 5830, but ensure you have enough cooling should you go down this route.
Should you have space for a full size card, then there is no reason to go with a low-profile card. Rather get a normal card which typically comes cheaper and with less noise. But again, for a small form factor, low profile high-power 3D system this is the graphics card to go for.