The most important advantages of ABS are impact resistance and toughness. Lego is made from ABS. It will also not deform in hot water, compared to PLA. On the downside ABS is hard to print. You need very hot printbed (around 110 degrees Celsius) and Kapton tape, so the first layer will stick properly. ABS can also warp and curl. There are also other issues in the Marlin firmware that need some attention.
If you are impatient and don't want to wait too long for your print to finish you can look for a solution in the E3D Volcano hotend. It is able to extrude filament a much greater speeds than a normal (V6) extruder. But it comes at a price of sacrificing the print quality.
It can happen that molten filament can leak from the hotend. This usually happens when there is a gap between the heat break hotend throat and the nozzle. This is the result of poor assembly of the extruder's hotend part.
The stepper motors are constantly pulling current. Without any cooling the chip that is on the stepper driver module would burn very quickly. Adding small heatsinks on top of the chip is of course the first step, but we can go a bit further.
Our 3D printer is finished, but we still can not use it until we program the Arduino board with software that will control our printer. There are several options for the firmware. I have chosen Marlin.