If you have an instructor to help you, I would go with the PT40 as well. I've had both planes but flies completely different! The Kadet is very stable, and IMO the most stable trainer out there, and its built like a tank. My PT40 is a blast to fly as fare as trainers goes. For a trainer it does a great job at roll and loops and feels very light in the air compare to the sig Kadet, and handles great at slow speed (for landing). Its really up to you. Both planes are well made but just don't expect too much out of kadet when it comes to having some fun once you have the grasp for basic flying. Hopes this helps