I realize that a gps unit is not what Mark is looking for but while at Oshkosh this year I looked at the Lowrance 2000C. I was really impressed with them, of course I do not own one nor have I flown with one. I have always been a Garmin lover but for just under $600.00 (at Oshkosh) I could not believe what the 2000C had to offer. I paid $1,200.00 or more for my gray scale Garmin195 years ago. I would take the larger color screen and features of the Lowrance 2000C any day, especially for less then half the price. One of the features that intrigued me was the color coding of towers that may be in your pathway and the color coding of terrain that was at higher elevation than your current elevation. It is WAAS capable or will be soon. If I understood or remember correctly it has street info as well. Check the site out below, I have looked at the site but it does no justice to the real thing. If you have a chance to see one in person then check one out I think you will be impressed also.
http://www.lowrance.com/Aviation/Products/AM2000C.asp Larry H.