I think your Little River Band comparison is pretty close, I didn't feel the Chicago that much. Oh well. Vocals seem pretty together - I think your splash cymbals might be a little loud, but at least they are panned well.
I think you might look at one of your "three part" vocal harmonies on the outtro, something wasn't blending quite as nicely, I think it's the high one, maybe just a hair flat in spots? Paging Dr. Melodyne?
I liked your arrangement, it kept the interest going. Nice tune, a throwback to the 70's I'm a thinking!
cheers,
-Tom