I'm using a tow dolly. I've never towed 4-down. When you first use the dolly to can be intimidating and time consuming. However, after a few times it becomes easy.
I rarely unhook the dolly from the MH... no real reason to unless the site you're pulling into is not long enough or not a true pull-thru.
Where I'm at now, I had to unhook the dolly because they have only back-in sites. There is enough room to store the dolly and park my car. Getting ready to leave tomorrow, I hooked the dolly up this morning. Took me 10 minutes. You have to put the hitch on the ball, hook up 2 safety chains, 1 emergency brake cable and the light connection.
I usually takes me 2 or 3 tries to get the car lined up, but once done, you have only to wrap the straps around each tire and connect the chains around the frame. Again, only about 10 minutes. I've never had to do any of this in rain or snow.
I thought about 4-down, but it would have required that I trade in my almost new car (Kia Soul) and then pay someone to make the modifications needed to tow as well as buying a Brake Buddy or something similar, for braking.
I'm very happy with my dolly.
Mike