I had a Saito .82 on a Funtana X50 - for a short while! It was great fun, until the left wing decided to go its own separate way! That engine and Rx is now running happily in a Showtime 50. The ST50 has a wing tube, and the X50 did not. I wonder if there had been a wing tube......
I felt the wing wasn't put together very well on my Funtana. It snapped right at a spar, and it looked like there was hardly ANY glue on it. I would have had to remove the covering to add glue in that area. But to be fair, I was NOT easy on the X50!
However, since I did NOT want a repeat performance on the wing, I bought the ST50 to replace my X50. The X50 was more wildly acrobatic than the ST50, but the ST50 ain't bad! And.... the wing is staying on - so far.....