Frankly this amp is superb. In performance terms it's better than I'd hoped and it's excellent value for money. You'll need to spend a lot more to hear any significant improvement and for your average living room it's more than powerful enough.
I've got a PS3, DVD (digital 5.1) and an old Sky box (stereo) attached and they all sound great. The PS3 in particular comes to life with both blu-ray and games sounding good enough to make you jump with surprise. The DVD player is as good and even plain old stereo from Sky sounds much improved. This is using Yamaha's very reasonably priced NS-P110 speakers - also recommended.
You'll need to buy cables for attaching your devices to the amp (such as HDMI and optical cables) as these are not included. It's also worth noting the HDMI ports are for video only - you'll need a separate cable for audio. I got some good quality speaker wire too - how much this improves the sound I'm not sure, but by cutting it to the length I wanted reduced clutter behind the amp/tv.
If you're thinking getting a 5.1 system for a number of devices but don't want to spend a fortune I can't recommend this amp (and the NS-P110 speakers) highly enough.