To address the safety issue: IN a collision with a fully loaded Semi hauling steel, I do not care, Car, Light truck, Motor home, You are toast. Forget it.
In a collision with a car or light truck.. Odds are I'm going to be sitting ABOVE the roof, clearly above the engine, and that car is or pick up may well slide right under me causing little if any injury.. So I do not consider the safety to be an issue.
The decision: If you move the rig often (At least every other month) a Motor Home is easier to set up and take down, It is very handy when you are on the road and feel the need to .... shall we say.... Pull off for a few minutes and go sit on a different seat. 5ers not so much.. Also though the MH only gets about 8mpg with the towed hooked behind it.. Said towed, per the trip meter and the gallon meter, Hit 28 on my last fill up (I bought it used 28-30 is it's rated MPG and it's getting there).
That honking big pick up which is really too small to pull the 5er might get 8 towing (The dynamics are very close) but likely won't break out of the teens bobtail.
OH, and that is another issue: I see far too many 5ers beign towed by far too LITTLE pick up, not that... Is a safety issue.. Of course on occasion I find one being pulled by www.trail-hauler.com and those I do not worry about so much when they pass.. I know that tractor can pull that trailer (The proper name for a Tow Vehicle is Tractor).