I bought one a few months back but I haven't been able to set it up yet as I've had a number of home maintenance disasters to sort out. I bought a bare bones 6040 without any of the electronics from ebay (RATTM Motor). The kit comes semi assembled and all the critically aligned stuff comes already pre-assembled. It looks fairly decently finished but the overall impression is that it has been designed to be just about adequate to cut soft materials like wood and plastics routinely and aluminium at a push on the odd occasion.

Professionals and serious enthusiasts here quite rightly point out that it is not an adequate machine for serious work, but for a complete noob like me seeking to teach myself CAD, CAM and CNC machining from scratch, the 6040 looks like unbeatable value. I can always flog it off on ebay for not too big a loss if I outgrow it.

I've bought good stepper motors (3.1NM) and drivers (AM822) and I am going to build the electrics from scratch with a view to retaining them for a machine upgrade in future should the CNC bug bite. I decided to go this route as the biggest cause of dissatisfaction and problems with these machines by a large margin is the electrics. I would suggest looking at this option seriously rather than buying one with the OEM control box. You will be able to sell it off easier and recover your costs even if it means spending a little bit more.

The vendor sent the item fairly promptly and it came well packaged. I haven't needed any after sales support but I doubt you would get any apart from a replacement for obvious damage.