I have heard that a lot of folks don't like the Cherry browns (or the Kaihls) but I don't have terrible problem with them. Would love them to be more tactile, but they actually do feel pretty good overall, and I do type better with them, which I can't ignore. It's weird.
Way back when I had an AEK II (salmon Alps, right?), which if course I didn't appreciate at the time. I'd agree that any vintage complicated Alps switch is probably better than a Matias switch, which I understand are basically modified clones of the Alps simple switches. Still, the Matias switches sound pretty good and really, really annoy my boss (over Slack, no less). Which, aside from being great, also tells me that to the extent that it makes me cheerful, I clearly still haven't grown up.
Can't ever remember using a Model M. Would love to try one one day.
Have you thought about getting a switch tester of any kind? I haven't tried the regular Kailh browns, but their box browns have noticeable tactility, and are very smooth. Much better in both regards than MX browns. People seem to be veering towards Zealios for tactiles though. Many people, even if they don't like browns, do seem to feel like they have some intrinsic efficiency to them. Many people report that they type fastest on them vs other switches. I'm not sure how that could always accurately be quantified though. Someone that's used to heavy linears, like MX blacks, is going to type a lot differently on MX browns for the sake of a short test, and so will people who use membrane buckling spring, etc.
AEKIIs can have Alps SKCM salmon, cream damped, white damped, or Mitsumi standard. Deskthority's wiki is a great resource for such things if you haven't stumbled upon it yet. The likelihood is high that yours did have some kind of tactile Alps. Yes, Matias is kind of the modern Alps torchbearer. they annoy your boss and you still use them? lol Is that why you're getting a Unicomp? For the pingy, clacky music?
I don't even know what cool old boards I may have had and gotten rid of before I even knew what a mechanical keyboard was. It bothers me to wonder about. I know I had piles of old beige keyboards since I have always had, and worked on, a lot of computers.
The reason I asked about a Model M is that Unicomps are basically to the Model M what Matias is to Alps. They're modern membrane buckling spring keyboards. I have never typed on a Unicomp, but the original Ms have relatively stiff springs. Stiff enough that I initially did not like how much they fatigued my fingers. I would imagine this would be even more jarring coming from MX browns, etc, as I was coming from MX blues.