The game is okay, but I find the rules surprising clunky for some reason. It may just be how the rules are presented or organised, or that there are so many exceptions/critical effects.
The game plays well with a handful of small 5-7 model squads, and you could quite easily just play the game with 20-30 infantry models each side.
Adding vehicles requires you to do such to both sides really, and/or play a minimum game size, in order to ensure that they don't dominate too much. Scenarios help here too.
As for the models:
The plastics are reasonable value if you get a boxed set/bundle. They are somewhat pricey if you just buy a single squad though. It's a shame that the options (especially for squad leader and command parts, but also for special weapons) are so limited on most of them though, as it would have been trivially easy to do - in this respect, the later kits are generally better than the earlier kits.
The metal models are lovely, and I have both my C3 and Algoryn forces in metal (despite also having a pile of C3 in plastic as well). Although they are more limited in some ways, I also find the metal models easier to paint, to have finer detail, and to generally be 1-peice (which makes preparing them for painting much faster).
The vehicle kits are mostly resin and metal at the moment, with the exception of the C3 tank and transport drones (which also double up for Freeborn). I don't have any direct experience of the hybrid kits, but the C3 plastic tank is very nice and worth the money I feel (it's even designed to be easy to swap the weapons out via use of small magnets).
The game also plays better (I think) on a table where there is lots of terrain. Much like 40k2E, the weapon ranges on Antares are very long, and so more terrain generally produces a better game as both sides are forced to move around more.
Embarrassingly, I started a painting log here on LAF a good while back, and I still haven't got around to updating it. With this new rules PDF, I should probably go back and finish the project off!