So I tested out Navigon's update last night for about 7 miles and the trip to work this morning, about 10 miles.
I can say that I enjoy the new TTS voice even better. Sounds less evasive, more natural-speaking of the language, and forms better grammatical sentences than my Garmin with TTS does.
Some minor issues; it started running slow when using up all the RAM when I was trying to do route planning, and when it did that it reset all of the settings, so I had to turn iPod integration back on, TTS back on, etc.
Also, it announces about .3 - .2 miles before your turn, and about 500 feet before your turn it announces again, but this time adding the sentence name onto the announcement means that it's just beginning to say the street name at the 500 feet turn and by the time it finishes you're already .1 mile down the street you just turned on, so may be improve announcement times to accomodate for the street names now included in the announcements.
Those are two very minor things however; the iPod integration is a lil odd (almost like creating a temporary playlist), but it is probably something on Apple's end that they had to create a work-around, and it is still AMAZING and much better than having to shut down the application!
I can say that although it does slow some times, Navigon works great on my iPhone 3G, 16GB.
Can't wait to see contact address format update so that it can recognize contact addresses without having to put the Address # on Address Line 1 and the actual road name on Address Line 2, and Traffic will be an AMAZING addition.
Also it is still lacking detailed, written-out step-by-step directions "mapquest style" that some like to read before navigating (especially on a less-than-flavorable iPhone GPS chip), but hopefully that will be in a future update as well.
Keep it up Navigon!