Hwy 13 isn't very interesting for sure but you need to know where to look. If you have time there are many different ways to get to Pakse or up to Vientiane. A friend had a sticker on the back of his bike and it read "If this bike is in a pick up - it's being stolen."
Part of having the motor and wheels is to ride for the price to ship a bike, you can ride plus a little more to Pakse and actually see more of Laos. A stop in Savanakhet, Seno or Thakek makes the run easier time wise and if you stretch to 3 days is you aren't in such a hurry - many options abound.
For those on the forum that would like information or help planning a trip and to keep you ride off the bus, email me and I'll be happy to write something up you can use a base guide.
Last time I was in Pakse I was on a trip and one rider had to fly to Bangkok and we did ship the bike up. While I was at the Lankham, I checked out the rides. Our bikes had just been beaten to hell on bad road and thrashed but looked in better shape than the ones there. I'd rent from Lankham if I wanted to make shorter runs but nothing big. There are never more than 2 bikes there at a time.
Laos is a rider's country. I'll support Lao tourism by riding the bike as much as I can and am strong in support of getting out somewhere different and seeing more. Bikes on bus rooftops don't do it.