The newer phones charge at a higher amp rate and do in fact charge while using Google Maps Navigation. I can run my last phone (Samsung Fascinate) or my current HTC Thunderbolt with the 12V car charger and they both will be at 100% full charge once I get to my destination.
With Google Maps you can select layers and turn on traffic so as to avoid high traffic areas. You can not (or at least I do not know how
) activate traffic avoidance within the Navigation, you need to stop and exit nav and go to G-Maps and activate traffic so you can see the roads ahead. Then you go back to Nav and you simply manually bypass the roads that are full of suck. Just like a Garmin, the Google Nav will re-route you as you detour from its suggested path.
My Garmin died a couple years ago and I don't miss it.
If I had the $600 or $800 for those high end waterproof and vibration proof garmin units that are cycle specific, I would have one.... but I'm to poor for that fancy stuff!
I lay my Thunderbolt in the phone pocket of the Joe Rocket XL Manta magnetic tank bag and leave the pocket unzipped and the flap folded open and under the handle bar cross bar while in towns or areas that I need constant input. Once I go interstate or any time I'm going to be on a road for a period of time I flip it shut and partially zip it. I just re-open the flap as required to check on things while I'm riding.