Ive used sidewinders since Dan first made them. For lining they are hands down the best machine ive used, coil or otherwise. Check my instagram for work done with them. I have just recently switched to the edge x for everything due to hand issues.

The sidewinders are finicky however, do blob ink and do need a bit of tuning once in a while. Needle wise I used mine on everything from tight 3s up to loose 14s with no bother at all.I think the reason you see them for sale is people buy more than one (customs and one offs etc) but you don't really need more than one.