1) In 4e there's just 'tripod'. Just one. A tripod. You mount stuff to it. GPMG, HMG, AGLs, TOW whatever.
So for my v4 spreadsheet, I drop from 6 tripods entries to one. Kinda nice. Maybe that's too few, but six is way way too many.
For earlier editions, somehow every major ground combat vehicle can be converted to use ETOH as a fuel source, but the mechanic who pulled off that miracle couldn't get my M60 to fire from a PLT... NLT HAD to be a separate entry. Think about that.
2) One thing I've noticed so far is that having a fixed target number (6), while subject to some mods, is better for solo play and fast table play than target numbers, DCs, and their ilk. Roll, under six, NOPE, six or higher, boom, good job. It's fast and intuitive and there's no worry about Easy/Average/Difficult/etc.
3) I do like the shift from 4 hour periods, to 6 hour shifts, as it's less bookkeeping, for effectively the same feel/results (who is keeping the vehicles repaired, who is hunting, who is on watch, etc.).
4) Archetype attributes are a lot better the 2.2's 2d6-2, in my experience. No one wants to play a game with a 1 in any ATTR.
Looking forward to seeing the Beta release! ;P