One factor not mentioned (unless I missed it) is the visibility, with a MH you have a view down each side all the time and likely a backup camera. The 5er you won't see both sides unless you are straight, so you need to rely on the spotter and your judgement of where the trailer is. I have a lot of trailer experience and a little MH experience (35' A Class) and I can back the motorhome in without a spotter if I need to, but the trailer or 5er I need a spotter or to get out and check things.
As to the toad, I have no experience so no comment other than I can imagine not being able to backup could be a problem and my parents (it is their MH) have said as much on a few occasions.
5er is probably easier to drive in to tight spaces, but all so easier to get in to a jam when backing up. Either way, I strongly recommend you always get out and walk the site and plan your route in to it before you start. I have been in a situation that I had to go around the block to turn around so I could approach from the opposite direction in order to get parked, it was on a road and in the middle of an S-bend with branches blocking entry from one direction, if I had not of got out to look first, I would have damaged the MH.
If you can, try renting a MH or drive a friends unit, I used my parents before making the final decision to purchase and I am very glad we did, it helped immensely to make the final decision between trailer and MH.
