Not surprised to see so many negative comments. Most guys, whether they fly turbines or not, are scared at 150mph much less anything over 200mph. That's why we see so many models now with no bypasses, keeps them draggy and the speed down...seems it's starting to be the norm to fly draggy slow jets now a days. But there's still a few of us that like to push it past 200
I think it's pretty amazing, and takes a lot of thought in how the model is built to withstand those speeds. I'd be worried about control surface flutter the most.