we have the garmin RV750. yes you can program for vehicle length weight height etc. However it has one noticeable drawback. you can only program for overall length, not TV and trailer length. So....... it will tell you to avoid roads when it sees your overall length greater than the allowed trailer length for comercial trailers. It doesn't distinguish. And many times roads have a length limit for comercial trailers as well as overall length.
Next, many states list height restrictions for the corners of tunnels. and again, it can give you bad info, based on bad input. Not garmins fault but the sources fault. Likely any GPS will give the same problem if you can set overall height.
I've run into this issue on roads I KNEW I could travel on, been their, done that.
Overall, I like ours, it's nice to have the shortcuts for rv related things like campgrounds, repair etc.
and we have the matching rear camera, works great on the back of the trailer.
IMHO if your looking for a GPS, and you tow, no reason not to go with the garmin or similar RV GPS for the extra features they offer.
2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2015.5 Denali 4x4 CC/SB Duramax/Allison
2004.5 Silverado 4x4 CC/SB Duramax/Allison passed on to our Son!