I had a set of M2 on my commuter, the rear seemed to leak from the piston seals as the pads quickly got contaminated and the paint had started to bubble like the caliper was corroding.
I just swapped them for the new clarks clouts (a bit cheaper than the m2), they seem to work fine, feel a bit less wooden to me than the m2 but that’s not particularly important for a sub £15 brake on a commuter.
Also came with olive and barb to shorten hoses. I shortened the rear using the shimano method so I didn’t need to bleed it, but the front has a lot of lever movement out of the box and i’m pretty sure needs a bleed (i’ve not shortened the hose on that one).
Overall seem decent, hopefully the caliper won’t go the same way as the m2 it replaced.
Also the clouts are in the CRC clearance sale thing that the current voucher code applies to.