Nice track and the mix is pretty solid.
Things are pretty heavily jammed up the center. It works, but I think you could really open it up and make it unbelievably stellar.
There's alot going on in this track and it's pretty much down the middle.
Take a look at your panning scheme. Try keeping just the vocal, bass, kik and snare in the middle and start moving things around left and right. My suggestion is for moving the mando and acoustic guitars to either side (kind of like what you did with the banjo). and see what kind of space that gives you and work from there.. You may find that the vocal will sit a lot better in the center space.
Also, the snare seems to be a bit farther up front then it could be.
Also, this is country, country tends to be very straight forward and a very technical mix rather than effect heavy, so there might a bit much reverb in there (try killing the reverb/effects and see what happens). The reverb might also be what's making the track feel not as spacious as it could be.
If that doesn't work then it doesn't work and keep the mix as it is.
All that being said, I happen to really like this track alot. I also checked with my "country expert" - aka my dad (He pictures God holding a mandolin lol) and he LOVES it.