I have a subway 1 for winter commuting and a virtuosso as a better weather bike.
For the money they are great bikes,sure you can get a specialized or a trek with a similar spec but they will cost you up to another couple of hundred quid,if you can twiddle a spanner you can soon set up the bike,especially given the amount of information available on the interweb.
People do Poo Poo
Halfords but for many of us they represent easy access to cycle related stuff,the nearest what i would call decent bike shops around here (not including mercian but that's a whole other ball park) do not offer fitting or test rides etc so its halfords or nothing.
As for poor mechanical skills i took my front wheel to be retrued at the LBS as it needed completely redoing after a lot of potholes and all they did was tighten a few loose spokes and yet the guy at my Halfords knows what he is doing .