[vacpress]

I have experience with this question:

I built several drivers jsut like the first link you posted - the $15.00 device. They were a bgreat learning tool - easy PCB to design and make - and making steppers spin "alll on your own" can be very rewarding.. However, they are slow, run hot, and most likely loose steps.

I have also used a xylotex board, untill i blew it. The $40 xylotex seemed very nice for the 10 minutes it worked. It runs much faster and cooler than the unipolar.

I have also used the gecko g201s.. These drives are very impressive for the cost, as we all know. For $114/axis you can get a driver you will not grow out of unless you move upto a large gantry mill.

The embedded electronics device is a cheaper alternative to the xylotex and likely delivers similar performance, but it looks like you need to know a fair bit about 'tronics to get it running reliably.