The Sprint is nothing like an Xcalibur. It will teach you little more about jet flying than operating a turbine-which is fine. But people who fly Sprints think they can go on to a 'proper' jet and that's only true if they had the ability anyway. The Sprint loses energy by its self, shut the throttle and its got little energy, also if you pull hard with Sprint it will turn or mush, do that with any of the Xcalibur range and it will bite...just like a proper jet. The Xcalibur has ducting, its clean and holds energy,so you have to learn to slow it up. Its the best jet 'trainer' yet.
Only the pilot can know if he's ready for an UF. Its common here to go from an Xcalibur to an UF, the UF will fly slowly, you can pull hard if you are smooth and it won't bite, just like the Xcalibur.
Its impossible to give someone a set up that suits them, without knowing the way a pilot flies. I set up most of the UF flown here, I don't set them up the way I would fly...my friends that fly my models generally thing they are a little 'lively' for them...but since they are my aeroplanes that's fine :-)
This video was a windy day cross wind, I remember the day as a guy who was thinking about getting an UF had been told not to because of its handling. During the day I was pulling quite hard and he commented it did nothing nasty, he bought one and got on fine...You decide.
Yes, a bigger jet is always smoother and nicer :-)
www.youtube.com/watch?v=OuM-MAIAzwQ