The one thing I would caution regarding this PSU is that it isn't modular. This results in the usual problems of excess cabling obstructing airflow. If you have the budget I'd recommend paying an extra £10 - £15 for modular. That said this is a corsair 850W for just over £100 which means rock-solid voltage, the 70A 12v power rail can cope with anything up to mid-range sli / crossfire setup and you have a 5 year warranty.
Product packaging and quality is great, slightly larger than standard for ATX but all this meant for me is installing a 90mm fan on the bottom of the case instead of 120mm.
My advice if you're building a PC is to not save money on the PSU. My old rig (going a few years back) had an Nvidia 8800 GTX, 1066Mhz Motherboard FSB and RAM, OC processor and RAID 0 SATA II drive. I picked up an 850W PSU for £50 and 4 months later my motherboard, processor and 8800GTX were dead.
£450 of ruined components because I saved £40 on a PSU. You do the math. I'm not saying to buy this PSU specifically but it is a nice budget option. Stick to anything by Corsair, Antec, Seasonic, Enermax and a few select others.