I haven't used any brand of 3d printers, myself, but I have been doing research into them as well. The Cube looks nicer than the Printrbot LC (Printrbot.com) but for the price and performance I would go with the Printrbot. The Printrbot LC costs $550 and it has a 6x6x6 print bed. I believe that the printing resolution is better on the printrbot, also, but I could not find that information on the printrbot website. I think I read it in the printrbot forums.
Also, I read something about the Cubify having cartridges. The Printrbot runs off of a spool. The only draw back to the printrbot is that, for that price, you have to put it together and calibrate it yourself. But that is something that I would be willing to do.
I think it was Make Magazine that reviewed both of the machines, and other machines, and they declared the Printrbot jr a better deal overall. The Printrbot jr has a 4x4x4 printbed and only costs $399. But it only makes prints out of PLA material.