Tried C25 today.
 

Tested C25 today. Killed .05 of the short time, But got it back after that.
After a little tuning. Didn't see much change with the C25 But when I went back to square one (C12) I picked up a bit all over. Air had gotten worse (still very good though) 650' plus we developed a 5 to 10 mph headwind.
The C25 has some potential but it's going to take some trial and error to get it to leave at 3000 rpms.