I bought a 6040 with a 1.5k ER11 spindle, black box (not the blue one) with a SMC 4-4-16a16b fitted(no need to connect to a PC.) It cuts plastics and both soft and hardwood easily. It also cuts aluminium reasonably well. That said, I've had a few problems with mine: limit switches breaking, limit switch wires breaking, a screeching y axis(caused by bolts under the bed coming loose) and bits n pieces coming loose on the z gantry. The pump switch in the box has also stopped working. And the pump that came with the machine could wake the dead.

If I knew what I know now, and if it wasn't for my poor health and money problems(something always crops up making me dip into my savings), I'd replace the machine in a snap. All that aside though, I do enjoy using the machine. It's not that bad TBH (it's like a bridge camera pretending to be a DSLR). If you do buy one, I'd look around. For that sort of money you may get one with a 1.5k WC spindle.