650Pounds to USD is about $1000~ and for the same price you could get something a little bit faster than the GTX 960 and a core i5-4690k instead.
But since you don't want to go through the trouble of building it yourself which is absolutely fine I say you're getting a good build for the money you are spending.
The PC you put down does come with 16GB of Ram, a 2TB Hard Drive, 120GB SSD and all.
But the only thing I would say about this pre-built computer is that once you buy the system that you replace the powersupply. This takes president over anything else because you don't know what brand power supply is in that computer let alone if it's able to handle 80%-100% load for more than a couple minutes.