BAR is more similar to the original Total Annihilation (and successors like Supreme Commander). It's a lot of similar units (e.g. tanks) with subtle variations, multiple tiers, with a focus on out-numbering your opponent.
Zero-K went a different route. They simplified the economy (metal cost = energy cost) but added a whole lot of mechanics like overdrive grids and made every unit unique. There is a lot of variety with mind-control, jumpjets, shields, unit-throwers, self-replicators, teleports, terraforming, etc.
Zero-K has been on Steam for a few years, I think BAR is working towards it. They are both good worthwhile games, they share some common elements, but they are both worth trying in their own right.
But if I'm not mistaken Zero-K's pulling/pushing beam weapons predate SupCom2 (combined with terraformed ramps you get a unit cannon, though making the unit survive on landing is an additional challenge), though Lobsters came out after :
Zero-K went a different route. They simplified the economy (metal cost = energy cost) but added a whole lot of mechanics like overdrive grids and made every unit unique. There is a lot of variety with mind-control, jumpjets, shields, unit-throwers, self-replicators, teleports, terraforming, etc.
Zero-K has been on Steam for a few years, I think BAR is working towards it. They are both good worthwhile games, they share some common elements, but they are both worth trying in their own right.