Is spinning a prop at a high RPM what is considered powerful? The equations don't necessarily support this conclusion. Basically, torque X RPM = HP. Torque and RPM can vary but still yield the same HP.
Frankly, the O.S. 46 FX will outspin the TT Pro 46 on the ground or bench using some popular prop sizes.
Me, personally, I could care less. It has been said by many either in person or on posts that the TT will outperform the O.S. I will never buy a small O.S. two stroke engine; above .91 is a different story but I would still be reluctant.
I can't stand grandstanding or overcooked hams.

Still within the 46 class size engines are the Irvine 53, GMS 47 and the K&B 48.
I've heard nothing but praise regarding these three engines. (I admit I was suprised with the GMS 47).
Oh, look! I threw another brand in the well to pick from!
The important thing about making a decision is not what everyone else thinks but what you think. Compile as much info as you can about your choices and make your decision based on facts, figures, personal experience of others, user friendliness, reliability, and power. Or, just blindly pick one and go for it!

Best of Luck,
Jeff