Hey Joe,

My son and I are both flying DS821's on ailerons and I do have a old focus using it for elevator too. These servo's are great in my opinion and I fly primarely Futaba. They are a carbonite geared servo so they don't wear like a metal geared servo and they are a little stronger than the nylon geared servos. At 6 volts they are at 88oz and a speed of .16. Don't be scared to use them and like Jon said you should use a servo on rudder that has more torque. Just my 2 cents.

Larry</p>