More evolution than revolution, but clearly NextGen is improved over Primo Android.
Two huge deal-killer bugs have seemingly been eradicated:
1) The landscape to portrait or vice-versa switch issue
2) The MAJOR sound bug..where you would plug into the headphone jack (or use bluetooth) to connect to a car sound system and the whole unit is diminished to a whisper

With the elimination of resolution sizes and a switch to "DPI", it should be much easier to set up on different hardware.,.at least it was for me..no more fiddling in sys.txt for an hour trying different settings.
I have both an Android phone and a WinCE stand-alone GPS device, and setup NextGen on both to be identical (including skins), in a very short time and with no trouble at all.
Basically they have kept everything good (without question the most customizable navigation app available, and much from Primo transitions to NextGen without trouble..car models, some settings, etc), and fixed much of the bad.
Though not entirely 100% feature complete yet, this will come with more licenses and more work from the 'fixer' geniuses.