I used VZNav when I had a Chocolate. I was going to use it on my BlackBerry but, as stated on previous posts, on blackberries you can't pay on a per use basis.
On blackberries, I have not seen a better navigator than VZNav. But I have not seen them all so one may exist. Two days ago I installed Amaze and it seems pretty good. I have the Storm, i pay for the data plan, and I understand why some folks prefer not to pay the $10 bucks if you can find something comparable free. If you drive a lot then it is worth it. I find myself using a navigator program maybe once a month.
OP - great thread. Very informative, brief and to the point. I wish I could find a thread that compares themes that was this brief AND this informative.