How much / how far will they be going? If they go RV (motorhome), do they plan to tow a vehicle?

I was in serious doubts, but went with a 32' RV, and after 6000 mile stroll up and down East Coast, with wife and 4 kids, i found that towing is unnecessary, as we managed to find parking in most places (even in historic Charleston, SC), right here: https://www.google.com/maps/place/2+E+Battery,+Charleston,+SC+29401/@32.771087,-79.9303856,17z/

Basically I think motorhome offers a lot more utility, because if you go into city, you only need to worry about parking 1 vehicle, instead of finding parking for trailer outside city, and then going in with the truck.

If your parents will go camping, it doesn't really matter, except if the plan to leave campsite often. Then truck + trailer is better.

I mean really it's what they will use it for and how much driving they plan to do.

I found that most motorhomes SWAY a lot on highways, making driving they not very comfortable UNTIL you get used to it. Took me 1500 miles to get used, but I did a lot of practicing on I-90, and I-95, both of which have a lot of truckers (like REALLY A LOT!!)

good luck