Goodgrouper, I hope I'm not too late for you to read this; but I too love 10X ! I got fantastic groups and speed in my 20TAC(driver) using 39gr. pills. By that, I mean 3892fps and groups consistently in the 3s. Out of an AR 15 !
One problem I found though that you should and may be aware of; it is very temp. sensitive.
That's the only complaint I have and is easily overcome. I could put 25.1 gr. in it at 50 degrees; but had to drop to 24.1 at 70 degrees. As for my 223AI; I want to shoot 55gr. pills in my 14 twist barrel and I WILL try 10X ! My upper builder used to get 3650 fps with an Accurate powder. They changed it and now it only goes about 3400. Bummer. And it was danged accurate too ! His go to powder in the 20 TAC (driver) is 2460; it meters great and the same volume of it is equal to my 24.1 gr. of 10X with the same velocity and accuracy. You can bet if I try 10X, I'm going to try 2460 ! One other caveat; someone said 10X reformulated. It's true; the newer cans show the word"new" on them. All I found was it burns a whole lot cleaner. Good luck on your quest and I hope this is informative and not too late.