So to answer OP's question, and focus on towing, not comfort, or stairs (or lack thereof) etc..
I've owned both. Currently on my first 5er.
I prefer the 5er towing experience. TT tow experience was fine when trailer is setup properly, but 5er is more stable in my opinion, especially in windy conditions.
Backing up - 5er is different. Took me some time to get used to it. Not really more difficult, just different. Think the TT reacted quicker to input.
Turning - 5er turns INSIDE the track of the truck. So, you have to take turns wider to avoid curbing the tires.
Other than that, pretty much 6 of 1, half dozen of another.
Mike