I played his Javelot, some other models and I also own 2 Thurau baroque triples.
Javelot is fantastic. It is super convenient to the body, with amazing sound, loud, very flying, but same time very clear and delicate. Great basses. Mechanics work silently, easily and perfect. Highest quality in everything.
Rainer Thurau is a great artist. He takes enormous care about every tiny detail. His instruments are brilliant and, probably, the best harps the money can buy.
I am envious too! The Javelot is the most visually appealing (to me) of all the Thurau harps. I would love to own one but alas, they are out of my price range. Would love to have a chance to try one sometime.