RE: YS 1.10 vs. O.S. .91fx for Funtana 90s?
Definately go with the YS 1.10FZ. I have a 1.10FZ on my FT90 spinning a APC 16x4 at 10,300. I actually flew my buds FT90 again today with a Satio 100 and was once again disappointed. Hovering is capable with a 15x4W on the 100, but only at WOT. The performance really lacks compared to the 1.10FZ. The Saito 1.20 would be a better choice, but still not comparable to the YS. The Saito 1.50 is a better choice if you are comparing the YS 1.10 and a Saito. Forget about 2 strokes for 3D. You'll be more happy with the 4-stroke torque.
Just my opinion,
DTB