Citation 500 series are all pretty small, especially if you are over 6 foot tall. I am 6'1", and when I adjust my seat in the Encore (CE-560) so that I am comfortable looking through the windshield, my head starts to rub on the ceiling on the side. Also, getting into the seat can be a chore if you are tall, as you have to get your leg over the center pedastal. The King Airs all have more head room in my opinion, but leg room is a little more lacking unless you put your feet between the pedals. The Citation 560XL has more of a stand up cabin, and more room up front, but still not in comparison to the Challenger and the like.