Hi, and welcome to the forums. You're going to get a bunch of differing opinions on your questions. Best advise is to go shop around at dealerships until you have the "Ah-Ha!" moment!
I've never had issues towing a travel trailer. I have not towed a 5er, but with proper tow vehicle and proper hitching, a trailer will tow very nice. My current arrangement is so stable, I have to keep looking in the mirrors to remind myself the trailer is there. The integrated brake controller built in the truck is what makes towing such a pleasure.
Far too many buy a trailer that is simply too much for their tow vehicle. And with "bumper tows" they cheap out on hitch systems. The secret to success with a bumper tow trailer is 1) tow vehicle rated for the job and 2) a hitch system that isn't junk! If you put $25,000 into a Travel Trailer, take the plunge and spend an extra grand on a good hitching system.
Same is true with 5ers. If the truck is underpowered or not sufficient, you'll have a horrible experience there too. And get a good 5er hitch. Spend the money and don't cheap out!
TT and 5er's each have their own advantages and disadvantages. Each is designed for slightly different functionality. And pretty much, TT owners say theirs is the best, and 5er owners say theirs is the best. At the bottom line, it's just a matter of what works for YOU.
Good luck ... you're going to get lots of suggestions and things you've never considered here. Take them all in good stride. Everyone is truly trying to give you the best advise based on their personal experiences. And those experiences re the BEST teachers!
Welcome!