The Zlin looks like really good plane. Should be very smooth. I have not owned one. I did have a GP 300 for a while and it was a great flying plane. I got kinda over confident and snapped it on a very short landing. Not busted up too bad, but decided to trash it anyway. It had some funny little quirks. Like the elevator felt kind of bouncy. It was a great flying plane though.
I do not like sticks. I think they serve thier purpose, but you are beyond that. I think larger control surfaces will teach you much more and advance your flying. Those little twig surfaces on the stick will be a step back. I was doing rolling circles with my extra. That was a blast. It was very effortless. I think the Zlin will be the same way. I only ha a saito .56, but it was plenty.