No reason.... Just thought it might be a good idea given that at least some of their shortcomings appear to be overcome by using shunt mod.
Thanks Robin, those posts are the best quick guide to what points really matter, that I've seen. Either I should read the LaserFAQ more closely, or there's stuff here that should be in there.
Are there any special points to specify op-amp choice with? I'm hoping some general purpose FET input type like the LF411 or LF412 will do ok, because that is incentive to make sure I have more of those around. Anything that can help narrow a good selection for a general part for many tasks is a good thing, it helps prevent that foul obsolescence problem that is occuring far too often now, as well as making it easy to get bulk discounts for stuff. Would that those LF411 op-amps were made in that tiny 5 pin shape you're using, those are nice.
One other question: could there be anything to gain from using high speed CMOS logic IC's like the hex schmitt triggers? The idea of building those into PWM oscillators and buffers for fast PWM proportional control is appealing, they're small and cheap, but I don't know yet what sort of risks they might have of overshoots and other nasties. I'll get one and try it but my findings are unlikely to be the best information to post here so I had to ask...