I've had patchy service with them. Twice the delivery arrived next day, no problems, but on two other orders they emailed me a few days later saying one item was not in stock so they were not sending out the order until it was in stock. Both times I emailed telling them to send out the order without the missing item. They did this after a few days, but I was charged for the whole order (including the missing item) and never did receive the missing item or a credit note or anything.
Both times the missing item was of very low value (around £1) so I couldn't be bothered to phone them up and try and get my money back, so it was partly my fault.