Subtrim, How much is too much?

Just very curious on this.
My subtrims I try to keep as close to 0 as possible and still keep the arms at 90 to the servo's, and for the most part I normally will only have between 8 to 23 for the subtrim settings at most.
If I start getting up around 30 than I look for another arm or position that will allow me to get closer to 90 to the servo.
The other day I switched out my 7CAP on the Esmart to the DX6I and the elevator subtrim had to be put at 45 to get the arm at 90. Needless to say, I quickly found a different arm that allowed me to get it down to about 17.

So, I'm just kind of curious on how much is too much, what say all of you?
George

as you already know, a less subtrim uses the better, I've never gone beyond 20 myself.