Yeah, I bought one recently and I specified plenty of upgrades so I have quite a powerful all-round machine with a focus on video and photo editing. 2600 XP, 512 DDR 400, 120GB 7200 drive, 128MB gefroce 4 fx5200, Sony DVD rewriter, sharp TD17D3. I place the order on the website and it crashed. I phoned the service centre next day - they were helpful and explained that they had a server issue. I was e-mailed back the same day and my order was confirmed.
It took a few weeks from when I placed the order to when I got notification that it would come. Maybe 3, maybe 4, I cannot remember. I had prepared myself for this because I think you have to expect it with any of the "low cost high spec" suppliers.
I specified Saturday delivery but received an e-mail saying the system would arrive Monday. Again a quick call to the service centre confirmed that they had actually dispatched it for Saturday delivery and it came as promised.
Everything seemed to work OK, but there was a bit of a blob on the Sharp TFT monitor. I was put in touch with another service centre and they agreed to switch the monitor new for old. It came about a week later by Securicor.
The system is good and works well - it's v. fast. After a few weeks I noticed I was missing any DVD authoring software and after a quick call they sent it on next day.
You also get 30 days software support and the engineers are pretty good and very helpful. The guy on the other end help me set up a LAN in my home office - giving support via my web connection at one point.
Overall I would say that it was not a faultless experience, but I have a good value system and Carerra put things right very quickly each time I hit a problem.
Hope this is helpful