As mentioned previously, first resolve the weight issue. Afterwards, if both towing methods are still in contention, you have to spend some time determining how you plan to use your new setup.
Personally, I prefer a trailer. I can take any vehicle we own, strap other stuff on the trailer, and most importantly, back up if I get into a jam. However, there isn't always a convenient place to put your trailer. If your plans are definite, you can plan ahead for trailer accommodations. If you are just touring and staying wherever convenient, the trailer can sometimes be an inconvenience.
Fortunately, over the years we've had the good fortune to acquire both a trailer and a flat towing setup. If I had to pick just one, it would be the flat towing setup. It is easier, quicker to deploy, and eliminates another piece of equipment to maintain and insure.