Hi Take Five,
Welcome to iRV2 and the Newmar Owners Forum. The Newmar Owners Forum tends to actually answer the questions you post.
I tow both 4 down and with a dolly (not at the same time
). It all depends on the trip we are about to take. The dolly affords the option of taking vehicles that can not be towed 4 down. I have used the Demco Kar Kaddy SS since 2005. It works as advertised. I purchased this dolly because of its' features, accessories and the ability to fold up to a small foot print. Also, the dolly will carry quite a bit of weight. This is important because, it allows me choices in the vehicles I purchase. The tasks to load/unload are different that connecting and disconnecting when towing 4 down. For me, I find the tasks equally irritating.