The main difference is that mine
A- has an heated bed which is vital when printing with ABS.
B- can print up to 0.5mm layers which is good for printing large objects fast (they both go down to 0.1mm).
C- has the filament spools on the back so you can use different width spools, (the Dremel is inside and it looks like you're restricted toa certain width of the spool)
D- has two extruders which is good for many reasons. I can have two different materials loaded or two different colours of the same material. I can set it to print two objects at the same time (within limitations). The main reason I wanted twin extruders is so I can put a finer nozzel on one (0.2mm) so I can do smaller more detailed parts and use the normal nozzle for the big parts*. There's no mention of the Dremmels nozzle size but they're usually 0.4mm
The Dremmels build plate is slightly bigger
Dremmel-230mm x 150mm x 140mm
Mine- 225mm x 145mm x 150mm
and it looks like it's been put together better (mines made in china).
*The nozzle size is also one of the limiting factors of this type of printing. Most printers can print layers of 0.1mm in height but the width is dependent on the nozzle. The image below shows a 1mm cube with a 0.1mm x 0.4mm (standard nozzle) and a 0.1mm x 0.2mm nozzle. (The coding at the side is how you build things in OPENSCAD).
*
