I had a Tom Tom navigation system on PDA which I had in the car and it worked fine. When I came to renew it I went to the dealer and he advised me to go with a Garmin Nuvi 250 which I have now and have no problem with. TOM TOM is the biggest seller here in the Uk but Garmin are catching them up fast ! I you are looking for a Sat Nav for both Truck and bike make sure you get one that you can plug in an ear piece so you can hear the directions on the bike. Have a look at these.
https://buy.garmin.com/shop/shop.do?cID=135
https://buy.garmin.com/shop/shop.do?cID=135