I got a PC from them around 2 months ago, A1 service, I had a change of mind after I had originally placed my order (I decided on a larger hard drive) this was done with no hassle whatsoever.
I was gob smacked at the control and choice of what I could choose from during the picking of the parts/components of my build. Basically from the case, motherboard, PSU etc.
I am really impressed with the quality of my PC. Having looked inside, you can see the tidiness and the quality of build, you can tell that whoever built it takes great pride in their work.
I'm sure you will be more than happy with your new PC (I was).