So i finally got around to trying these out. I traded my backup pair of Ace 44 to a pal for a set of 144 mindys and I have to say that they exceeded my expectations but only because they were extremely low to begin with and only after I tweaked them a bit.
They're noisy as hell, even after lubricating the pivot cups, bushing seats, and washers. It silences them temporarily but the squeak comes back after a little.
They're heavy on the scale but I didn't really notice it when skating them. This may have been because I tried them out on a fairly steep deck (at least by my standards), the Scumco KT "dukes" 8.25. The fact its PS stix wood which has a very light and snappy pop feel probably helped nullify the weight as well. They really didn't feel significantly heavier than the trucks I previously had on the deck (Film 5.5 hollow) despite being like 50g heavier.
Turn was acceptable but not great. They don't turn as well as traditional kingpin indys and I did run into wheelbite issues with anything over 53mm. I ended up switching over to 94a aftermarket indy bushings which helped but didn't totally eliminate the problem. I don't have a ton of experience with inverted kingpins so I'm not sure if the worse turn is normal or not but I definitely noticed it with the mindys.
Grind felt a little weird too, a bit sticky. Adding a little bit of wax to the hanger helped but like the squeak issue its a temporary fix and I had to reapply it after a half dozen or so slappies.
Overall they're kind of a wet fart. I would say that unless you're some kind of smith/feeble specialist there's really no reason to get these over hollows. Forged plate indys are almost the same height but are lighter and turn better.
I ended up just swapping the baseplates with a set of 139 forged hollows and I like them much better that way. I wish they had just started making the lows again, maybe with a 144 option.