I recently bought from tekheads despite somewhat poor reviews here and elsewhere. (I read the reviews first but tbh having worked in customer care before it sounds like tekheads weren't entirely to blame in every case)
Contrary to these reviews, I was very very impressed from start to finish. My order for the various bits and bobs for a PC I was going to build was processed quickly as soon as my bank had corrected the mistake they (my bank) made and dispatched. Everything arrived in good nick, but I had to return some RAM as I had inadvertently ordered the wrong type when my original choice was out of stock. This was dispatched and I recieved it the next day at 9AM! I built my PC and got it running, no problems with any of the bits.
Then a couple of days later I discovered my surge protector (which I've had for years) wasnt and didnt. The PSU blew and I had to return it; tekheads didn't even argue, just replaced the PSU, which I recieved quickly as well. Now everything is sorted; I have a very good system and a big smile on my face. I recommend Tekheads.
I spent just over half a grand on kit so its not like I'm a huge customer but they treated me very well.