I am firmly in the "best ever" camp for the Grumman Meter series. My folks bought me one when I was 13 and it's still going 45 years later. I now have 3: two 3.8's with 25hp Mercs and a 4.6 side console with a 50hp Merc. Three of my buddies have also found a 4.4s that are in almost daily use, so now we've got a half dozen on the lake!
I'm redoing the transom on all 3 of mine (amazed they lasted this long) and the false floor in the 4.6, plus wiring. I've rarely had any leak issues and are easy to fix. Solid, stable and fast if setup for it. They will outlast me. As you mentioned they are hard to find and not cheap. I saw a 5.0 + ETEC a few years back I should have grabbed. The 5.0's are very rare, so congrats on yours. Would love an update if you see this.
Cheers,