I found the service very professional: I'm in France and I commanded a shirt on Redbubble and although it hasn't arrived on time, I had an excellent reactivity from the support service and they finally sent me a free replacement tee that arrived very quickly. I guess the transporter is responsible for this issue and the quick answers from the support were really pleasant.
For the product on itself, I have nothing special to say. It is exactly what I expected and it seems to be of good quality, but I can't say anything about the long-term quality.