If you build aroute in TripWizard and import it in BasCamp (BaseCamp will do the changing, given the vehicle profile you have there). I have never seen my Garmin 770 change the route I built in BaseCamp. Careful when you do the work in BasCamp that you are consistent in the profile you choose, and use. That's just my personal experience. I did experience those route differences when I was using other planning applications, exporting and importing to BC then onto the device. Definitely have to review the route in BC before putting on the device.
Also be sure the map versions on the device and in BC (if you have the maps installed there) are the same.
There are definitely a lot of "gotchas" in BC. BC has be come a challenge to me. :C
I would love to beable to get by with an on-line app for navigation (do it all the time in my car) but for the RV and the places we go (lack of cellular coverage) they are just not reliable enough. I use both when in the RV. AND have paper maps as well.