I've not heard of Frontier Travel, but a couple of years ago, we rented some bikes in Ho Chi Minh and rode all the way up the length of Vietnam to Hanoi. Did not realize that the entire length of Vietnam is almost the distance from Canada to Mexico! Took us about a month of leisurely travel.
Food was amazing!
So much diversity in the geography, from mountains, to beaches, cities to dirt roads in tucked away rural villages.
As we got closer to Hanoi, there was some really good dirt riding in the north. It was the wrong time of year for that and we were running out of time, but we have plans to return and just spend a couple of weeks doing some trail riding up there on some dirt bikes.
If you ever get a chance to ride Vietnam, do it!