I was very relieved not to go through that hell again when installing the OTR demo.
User interface is very slick and intuitive.
I was playing on General level before I even read the readme file. I especially like the relative altitude numbers on the plane icons. The planes also have colored icons to represent higher or lower alts, but I didn't find these to be of much use. The only problem I had with the interface was with the control stick lock. It wasn't a constant problem - sometimes it would work, sometimes not.