I've already backed this one, and importantly for myself confirmed that once the Kickstarter's over you can swap out the Americans or Russians for duplicate sets for those wanting just one Nationality.
Its unfortunate that the vehicles will only be unlocked at the highest tier, but hopefully when they go onto retail the Bumerang in particular won't be too expensive. That turret would be really useful for a bunch of modern Russian vehicles, in particular perhaps a conversion of Empress T-14 Armata into a T-15 (or sticking onto a BMP-3 to turn it into a drone).
I haven't looked into the rules, but being their previous ruleset has been reviewed well this may be what I was looking for in larger modern games. Spectre: Operations has turned out to be more of a combat sim than a wargame unfortunately, so it doesn't really scale for vehicles (when you can one shot a soldier with a rifle, a 30mm cannon is overkill...).