This mod is awesome, the base game is also great i think most of us have just played the vanilla factions map etc so many times that we need something fresh. The models, armor, factions, mechanics in this mod are so so so good and from my perspective much more replayable than vanilla, so while i would probably never play vanilla again i could play 1000 eagle rising campaigns and not be bored. That said, yea the main complain everyone has right now is realistic battle mod (rbm) which is now required to play eagle rising. I still recommend buying the game and even trying eagle rising with rbm to see what you think, it just gets frustrating fast, i think rbm it the culprit behind many/most of my crashes, and it makes battles way less fun.
Overall, i say yes game is worth buying, yes eagle rising is awesome and worth trying even with rbm, and if you are able donate to the team on nexus mods so they can keep improving & ideally incorporating community feedback.