Trailer options for a Duo Discus

Has anyone had experience of specifying a trailer for a DuoDiscus.

Specifically looking for any useful information on the X version with winglets.
I have the brochures for Cobra (Spindelberger) and Komet (Anschau)

After the cost of a DuoDiscus XLT the trailer is not going to be that
significant - but the hassle factor of a bad decision could be huge.

So - opinions on the welded versus bolted frames, and aluminium versus composite
materials welcomed.
Particularly interested in how the fittings work. Which of the arcane and
obscure German options translates into something worth having...


Thanks
Bruce