With the raid controller, I just worry about swapping the controller as in my experience that doesn't always work well, and I have about 13tb of data I can't lose on my raid. I am working on finding someone I can temporarily back that up to now, and then I will happily just run unraid.
(more info I forgot to mention in the OP) I am currently running a 8, 2tb drives in raid 5 with that rocket raid 2720sgl.
I have extensive experience with freenas, dockers seem like an easy solution however, and I'm willing to entertain anything.