PC quilter requires a special carriage setup, unless you get the more expensive side mounted version...if so, you loose about 10-12" off the length of the table for quilting. Set up is more involved than Qbot. PC Quilter uses a text format for the files, and you must hook to a computer to use it...so you need a computer dedicated to just the pcquilter...an added expense.
Qbot is a computer in itself, it's mounted on top of the sewing/quilting machine. You have two motors (X and Y)...X attaches to the lower carriage, Y attaches to the upper carriage. You have wires that are connected to the frame (for X), and to the lower carriage (Y). Once assembled (takes about 1/2 to one hour)...you put in the SD card with the designs on it, turn the Qbot on, choose the design & area...and quilt it out (I skipped the setting of the area, but it's easy to use). If you want to do freehand quilting, you don't have to disconnect anything...your table is free (no belts,etc...wires are out of the way of the table itself)...with PCQuilter, you have a belt that runs the length of the table. You set up the design on the computer and send it to the machine. If you want to do freehand, you have to move the machine to a seperate carriage system, or disconnect the pc quilter..takes a long time...much longer than Qbots setup. If you have the side mounted PCQuilter...you have to disconnect it...takes couple minutes or less. For the cost & ease of use...the Qbot is the better choice. in my opinion.