Yeah, every once in a while I return with another hobby... 2D, 3D, Scale Modelling
Really like your ED209! Looks as close to the Movies as I remember him.
Your Cain... Hmm... There are some things that bother me but please take them as an opinion, not a fact I would insist on:
The Chest front looks a little squashed in height - As if you tried to model a VW Beetle and ended up with a Porsche - Could be an issue with the camera angle.
The Chest Hydraulics could use some more diameter to make them appear less fragile.
The Gatling Arm looks kind of thin when compared to the Material I based my model on.
Hard to tell because of the rather glossy material you used but it appears you're missing those edges and cuts dividing the center top chest area both vertically and horizontally.
Everything else looks like Cain like how know him ( minor some details related to artistic freedom )
Maybe if one day I feel like it I'm gonna make a version that does not necessarily look like the Movie version but rather than a robot that could be build - Like that Boston Dynamics Atlas or PetDog.