I spent close to 45 minutes on my back yesterday inspecting the underside of a 2015 21 RBS as part of my PPI (welds, tanks, plumbing, propane lines, etc.) and found some cracked welds.
I'll try to explain without the aid of a drawing. Anyhow, visualize the main 2"x4" (?) rectangular tube that runs down the centerline of the trailer from the tongue back to a cross member. I see this fore and aft member (front to back for the land lubbers in the room

) as the back bone of the trailer or at least a VERY integral part of the structure. This main fore and aft member is welded to a cross member forming a "T" that, in turn, is welded to the outer frame members that also run fore and aft. I found cracks on 3 of the 4 welds that secure the cross member to the outer frame members on both sides of the trailer. There are gusset plates under these points where all the members tie-in to the intersecting member. I'm sure it can be repaired by a qualified aluminum welder. Am I ready to take on the responsibility after purchasing, then coordinating the repair? No. So unfortunately this was a deal killer for me.
I honestly believe that the owner had no idea these cracks existed. I am sharing this with the forum so they can inspect their travel trailer underside. Cracked welds were suppose to be an issue in the latter year models in the A Fame, not this early. (This LL had a manufacture date of 9/2014).
It was a great learning experience for me as this was the first time I've seen a Livin' Lite in person. This event does not change my opinion of Livin' Lite one iota. If anything, my observations during the rest of my inspection confirm my opinion that these trailers are extremely well built. The fit, finish, and quality of components are great. It also makes me think that Thor bought out Livin' Lite just to shut them down. Similar to what the major auto manufacturers did with Preston Tucker in the late 40's. I've digressed.
My search continues.
Cheers