I like mine selectable. I have a modified choke in the bottom and use it for singles so in this case I have the bottom barrel fire first. Now I have a full choke in my top barrel and when shooting handicap I have the top shoot first.
If I was shooting doubles I would set the bottom to shoot first of course. I like the feature and would use it in this fashion even with different chokes.
My old O/U had the same feature with fixed chokes. Improved modified on the bottom and full on the top and I used it in the same way.
For trap, I think it is an important feature. I don't know how it would work without it ?
Clay, in your O/U that does not have the selectable trigger, what are the chokes ? are they fixed or not ??
If they are not fixed it would just be a matter of changing chokes to suite what pattern you wanted to fire first. Kinda a hassel really.
Jacky