I have found that the os 1.20 AX 2-stroke is a No-brainer when it comes to tuning.
The saito 1.25 on the other hand is a-bit dif. experience...
It is easier to burn it out if you are not tunning it correctly. by ear, isn't were it's at...like on the 2-strokes...
I even consider myself a very good tuner...just not as good w/4-strokes apperntly.

If guys are needed tail weight, then the saito 125 would be perfect...
great running engine. Too bad the 50th anniversery sale is over...
I picked up mine for 300$ shipped! From advantage Hobby.
Compared to OS 110 for 450$...Yikes...