We were at our place up north this weekend and I stopped by the Watervliet International Airport and met Brenner and got to watch his plane fly and another fellow who's name I didn't catch fly. The planes make an interesting noise, not like a twin, but it was not objectionable either. You certainly knew that it was different. The thing you really notice is the constant speed, especially in the verticals. Power was beyond adequate (at least from a bystanders viewpoint).