Some of these posts are stated with such conviction it is fascinating. Look, yes some people say this or that to justify their purchase while others truly believe one app is clearly better than the other. Its SO dependent on how you use it, where you use it, when you use it that what I care more about is a well thought out post on the comparison between the two. This is what is truly helpful even if i do not agree.
Anyways...
I posted this the other day after having used both TT and Navigon for a few days.
https://forums.macrumors.com/posts/8300108/
Having now used both for longer, I have the following observations:
1) The clear lag TT has in routing (vs the built in compensation of Nav) is not as bad as I perceived. It is slightly more "choppy" than Nav but it always announces the turn before it comes up and the clear legibility of the street names, including the one you are turning on to, makes navigating almost as easy using Nav.
2) Two navigating features on the Nav which are heads and shoulders above the TT, for now, are the navigation arrows and the frequency of voice announcements. TT has one simple arrow showing you which way to turn. The navigon can display two arrows at once for those tricky turns where you need to turn right and then a quick left. I find this very helpful as it give me visual forewarning. The arrows are also overlaid on what the intersection looks like. If its a fork, there will be an extra white line (compared to an orange arrow) showing you which way to go in the fork. If its a 4 way intersection, you will see 3 white lines and then the arrow overlaying the 4th white line which is the way you are turning. Simple yet very effective and helpful. Frequency of announcements is also superb. Navigon will say things like "Proceed for 6 miles on current road", then "turn right in 2 miles", then "turn right in .5 miles", then "turn right in .1 miles". I find the less I have to look at the GPS the better and i have to look less with Nav than TT. TT's warnings are not as frequent. They could easily improve this. Side note: These apps will both eventually have TTS but right now, the fact that Nav will announce all major highways by name is also extremely helpful. TT does not do this.
3) Lane Assist/Reality Pro is great eye candy and it certain instances helpful. I was driving in upstate PA and kept switching to different state routes "PA this or PA that". Showing the lanes, which I have to be in, the overhead signs, and including information like the exit number is no doubt a nice, helpful feature and I see no reason why every GPS app should not have this. That said, i do not think this would be a "deciding feature for me". Its a nice to have but not a have to have.
4) The ability to pinpoint a location on the map when you do not know the address is MUCH easier on TT than on Nav. On Nav, you click Show Map, and then you can set and move a destination to exactly where you want - the problem is that getting the map to even show a location near where you want to pinpoint is a hassle and then when you are close, the Nav does not show many if any street names. This makes setting the location difficult. On the TT, its easier (although still a hassle) to get the map close to where you want to pinpoint but its very easy to pinpoint. The TT uses a magnifying glass through which you can see all the street names. You can even target a POI which is also shown on the map instead of searching for it. Much better implementation on TT. I have had to use it many times up here where addresses are less frequent. I think the reality is 8/10 places i will ever travel will be found via address or POI, but nonetheless I have appreciated TT's ability to make this easy for me.
5) Where TT shines for me is in the routing features. The ability to see the route instructions, which is more important for using the Avoid Part of Route feature then necessarily just seeing the route ala google maps, is a huge plus. I love being able to choose a certain road on the fly as I am driving, tell TT to avoid it, and then it quickly recalculates a new route for me. Simple, elegant and a must for all GPS apps. The ability to always, easily recalculate your original route again is a nice feature that I use. Easy access to a Route Demo is very helpful (on Nav, you can only get to it by creating a new route with 2 waypoints or if the GPS signal is not available). Although for both, I hate that you can not speed up the simulation like you can in Gmaps.
6) I find the voice more clear with TT on the loudest setting than I do with Nav. Nav on the loudest setting is very tinny. However, I hate the way TT handles overlaying a voice prompt when playing a song or podcast - it stops it completely whereas Nav lowers the volume gradually. This should be fixed.
If you read my original review, I think you will see I was a Nav fan. However, having used the TT more, I really like it more than I thought originally. Its really a tough choice as I still prefer the 3D view on the Nav but at the same time, i like the cleaner look of the TT. As these apps are still in their infancy, I am certain i will be jumping back and forth as each adds new features. And my bet is on Nav to add/fix features more quickly than TT. They have already announced some great new updates that I am looking forward to.
Sorry for the novella but hopefully this is helpful for people trying to decide.