I love him! Saw him go at WEG and he was one of my favorites. He looked like a very nice ride. However, I've been told that it took years for him to develop that rideability, and he wasn't always so easy, FWIW. I haven't researched him in depth, so don't know what (if anything) he has sired. Certainly he, himself, is quite an athlete, but whether he is/will pass that on I don't know. I believe the semen is $2100/dose.
We had the opportunity to speak with Marcus directly about Plot Blue at WEG. He verified that he took a long time to mature and mentioned that he may seem as though he needs more blood when watching him around a course, but that to ride he was quite sensitive and alert. He also told us that he had one of his own mares (a For Pleasure) in foal to him for next year.
In regards to Mr. Blue, a breeder sometime ago told us that she had bred to him and the resulting gelding was quite, how do you say it, dumb....
Apparently he kept running into trees! Perhaps however this was an isolated case with this Mr. Blue gelding.
I know about some foals in Germany for hanoverian Verband and know some quite good jumper breeders that bred to him. And also that some breeders arranged that he was finally presented for hanoverian breeding license. The owners were not that interested in it.
We could see him at some shows broadcasted on TV in Germany and yes, it did not seem to be a push button horse. But that is what real jumpers do not really expect from my experience.
But as jumping is not really my area of expertise, I can not comment on the horse as a breeding stallion and his traits, positive or ngeative.
Mr. Blue comes from a long line of VERY late maturers so I'm not surprised he took a long time to develop. We all know that brilliance in the show ring is often combined with sensitivity. I think this is why he was so successful.....