I've been interested in upgrading to his newer boards, but I'm not sure I want the added complexity at the moment. Have you used the generic modular one? If so, how does it compare to the older one I linked to?

Interesting question; I just had to go through this myself. I really only wanted 3 axes and considered the older one you linked to (which isn't marked 'retired', but is "out of stock"). The first thing I'd mention is that the older board doesn't support the new style of drivers (old = TI DRV8825, new = Trinamic SPI). SPI drivers are much nicer for a number of reasons, in particular you can change the motor current via software, and with the trinamics there's support for stallguard.

In my case I'm not building a CNC, but controlling the axes of a microscope (X, Y, Z) plus the intensity of the illuminator and likely several other things, so the 6-pack (which I also use on my CNC) had what I wanted.

Oh, you can also use either onboard or external motor drivers with the 6-pack- external motor drivers are good for NEMA23 and other large motors.

I've heard so many good things about Trinamic drivers, but never had a good opportunity to use them! I'll be fixing up a friend's 3018 generic soon, might be a good time to give them a try. Changing current on the fly is a killer feature!

Nice, we use CNC microscopes at work for automated feature dimension measurements, they're incredibly useful for validating milled parts and inspecting wear patterns over time.

Thanks for the info, I'm going to have to upgrade again soon it sounds like!

TBH, I haven't dived into the stall detection in Trinamics, but the goal is to eliminate end stops on my scope.