Both are great for what you are talking about. I have this years Union Force DLX's and they are very light and nice. Super responsive. I am going to throw them on my splitboard once the resorts close down this weekend. Great binders for sure.
390's perform equally well. About the only knock I'll give them is that I didn't find them as comfortable as the Force bindings. That's about it, and by comfortable I am talking width of a butt hair difference