I've only toured on an mtb with panniers and it works so well I see no need to look into a touring bike, or a trailer. The mtb is rigid frame, an old Specialized Hard Rock 7-speed. Stock gearing. Out of curiosity I once weighed my racks and panniers (Ortlieb Front and Backrollers) to compare them with the weight of a trailer (BOB Yak Plus) and the Yak was heavier by 4 pounds. I am not by any means an ultralight tourer and have no desire to become one (bike, bags, gear, food, water, and the kitchen sink, usually weigh in at about 80 pounds), but an extra 4 pounds is too much for me, especially when panniers already work so well. If I had a lighter bike that might not handle the weight of the panniers so well, I'd definitely look at the Yak though. To each his/her own.