Steve,
I recently changed from a Saito 1.00 to a YS 1.10 on my UCD.
No...I'm not going there.
With the 1.25 you will need to be very conscious of throttle management.
I'm now running a 16X6 and flew it extensively for the first time this Sunday.
I broke a servo arm on the aileron...don't know how...never heard any flutter but I did a lot of WOT straight and level.
The 1.25 will pull it like a rocket...just be careful.
JLK