Ok, I see your thinking, I was thinking that solid navy was even more city/formal.
I actually prefer it to, say, a button down or a semi-spread. It kinda pushes the bow forward in a way the others don't so it spreads forwards more, making it seem a bit narrower and less affected in my opinion, but your mileage may vary. It's my preferred way of wearing them outside of a formal environment.
I'd say a tux is one of the easiest ways to dress, because there is so little variation. Everything has to conform to a basic set of rules: Black/midnight blue, peak/shawl lapels in satin/grosgrain, jetted pockets, no splits in the back, 1 button/double breasted, wear a white double cuff shirt, black bow tie, waistcoat/cummerbund and black captoes, and wear it after 6pm/sunset. If you're looking at a tux and it doesn't conform to these rules it's not really appropriate. You have to choose for yourself whether you're ok with that. I don't mind a little deviation, as long as the basic details are there.
Thanks for the compliments/thumbs guys, it was a great night!