I started off early with in-car navigation back in the '90s. My choice at the time was Alpine. I've had at least, four different Alpine navigation units by upgrading. What I found with each one though, was that they weren't necessarily better. Each new unit was slightly more of a PITA to operate. Not only that, the search function was, and judging by the last one I had, IS HORRIBLE! After not only having the nav units, I'd been through numerous high end Alpine audio head units as well.
To jump brands was not an easy decision for me to make. I felt like I was cheating on my wife. I ended up getting a Kenwood navigation unit, and have been using Kenwoods ever since. SO much easier to use. SO intuitive. They made the right choice teaming up with Garmin.
Now, don't get me wrong, I have had a few high end Pioneer decks thrown in there as well, but not navi. I loved the audio units, and the features they packed, but ended up with Kenwood. I would suggest going to an audio shop, just tell them you are only looking today. Of course, they'll try to do the hard sell, but play around with the new units. You may find you don't like something about one of them that you picked.
I've done that before, and I was really turned off by something a head unit did. It changed my mind right then and there. You may also find a different one that you don't have listed that you may like more.