I believe this is a good deal for 4th gen i5 all in one from a good brand. Beware there are two types one has Intel HD graphics and the one below has 2Gb dedicated. Seen this in action in john Lewis for £799 but with an offer of three years warranty. As always try before you buy.
Intel Core i5 4th Gen.
2.5 GHz or more
8 GB DDR3 RAM
Hard Drive Capacity
Graphics Processing Type
Nvidia GeForce 705M 2GB Dedicated Graphics
DVD Rewriter (Dual Layer Super Multi)
10/100/1000 Gigabit Fast Ethernet
Integrated Stereo Speakers
Multi Card reader
USB Keyboard & Mouse Only
4th Gen ntel Core i5-4570T 2.9 GHz Haswell, Nvidia GeForce 705M 2GB Dedicated Graphics