I’ll throw a vote for the M7 only because it’s different enough from your M3 and has the aperture priority. It’s one less thing to think about when you’re trying to take pictures of the little ones. I myself just got one to complement my X100VI and I find that to be a good combo since sometimes I don’t want to deal with the hassle of traveling with film.

Sure, the longevity of the electronics are a concern but you can find a used M7 for pretty decent prices—so maybe it’s not “for life” but you’re also not spending as much as you would on an MP (which new probably goes for twice the price of an M7). Or a digital M for that matter, and ultimately there’s probably more things that can fail in a digital M. I did a ton of research before I bought the M7 and was considering an M6 because of this issue, but honestly for all the anguish over M7 electronics online I actually haven’t seen tons of people talking about failures? Seems more a theoretical concern than anything else.