ive used CRC several times (well about 8...all over 250gbp).
theyve only sent the wrong thing, was a pair of crappy michelins and they werent in the box, they arrived a week and a half later (to australia) after a quick email. i was happy.
and because im an indecisive bastard i asked them to change the colour of my hubs. which they did, but accidently charged me for two sets of hope pro 2s. another quick email and they had refunded me the cost aswell as an international bank fee, that they really didnt need to do.
i was very happy with that.
ill keep buying from them when i need to, they are still the cheapest and their customer service, while a little slow is still pretty good.