I thought it was an excellent question to ask.....as to why he would disconnect. Often people receive terrible information from other RVers and really need to explain themselves when they ask a question like he did. A little more explanation provided the root cause for his question.
As a matter of fact, I think the OP actually received terrible information from other RVers....the ones who told him to disconnect. Where is the money and time savings by disconnecting. He's not driving a 1960 VW bus, towing a VW Beetle. He's driving a modern day motor home with more than enough engine power and braking power to tow up and down any grade in the country.
I don't see the fuel savings when you're now driving two vehicles up a grade under power or the time savings by stopping twice to connect and disconnect.