I have no personal experience with these trailers but they aren't much more than a Thule car top cargo carrier (a small one) with a lot of lip stick and eye shadow. For what they are they are #$%@ expensive! I don't know what kind of price you are looking to pay for it but I'd bet you could buy a trailer of higher quality and more robust design for the same $$$$. JMHO
I seen the Road Dog GT at a rally and I was very surprised how soft the suspension was for a torsion type suspension.....most torsion type suspensions are very hard and won't move much when you push on the trailer, but the Road Dogs suspension compresses easily. I've never seen a torsion type suspension work as nice as the Road Dog trailer does....watching the Road Dog being pulled on their website video you can see the suspension responding to the smaller road inperfections and Road Dog looks like it's very plush riding. They are a nice looking trailer too IMO....and made in America.
But have hands on at CyclemaxOhio. Fit/finish was excellent. Roadies say on the suspension is correct. Seems softer (thus easier on contents) than other trailers I've looked at. If I was in the market I would consider it.