I have bought 2 home PCs from Mesh but I have always made sure that I knew I was getting good quality components. For example, I have upgraded the monitor, sound card, etc. to get what I want so I cannot comment on the quality of their basic monitors, etc..
If you look around the Mesh site you can always find the latest PCs that have been reviewed by PC magazines and these always seem to be better value for money (using better quality stuff, etc.) and are a good base for a PC.
I found that to get the cheapest offer you need to look at all the PCs available and choose the one that has almost everything you need and only upgrade a couple of things.