I used to have an X5 (2003 3.0i). I could not have been happier when I switched to the H2. It's been reliable, so much more comfortable than that car, and still will zoom around when you mash the pedal. Obviously, you can't pull a .91 on the skidpad or do 55MPH through a slalom, but it depends if that's important to you. The H2 will handle fairly well, but you have to get used to not being able to stop on dime. It takes some time to change your driving style up a little bit (like not tailgating, or passing when you have just enough space
). The size factor will disappear very quickly (it's a shock, but trust me, it will soon feel normal), but drivethroughs will always be somewhat intimidating.
As far as towing, the H2 will do it very well. The tow/haul mode can be engaged for this, and it moves the shift points so you remain in a lower gear longer. I know a woman that uses an H2 for her horse trailer, and is very happy.
Hope that answers some of your questions.