on the stroke is a matter of the user... some like short stoke and fast moving and some like a longer stroke and slow machine,it depends on the artist style... I have 5 stealth and 2 gen 6... I have 2 of them with 1mm stoke and use for blk & gry I like a fast moving machine for blk and grey to get smoother blends I also use long tapers or bug pins. and I have pushed 15 and 23 mags with these machine.. I use the 1.5 mm for color and some blk and grey I use the gen 6 for linning.