so which choke would you use for skeet and which would you use for ducks?
I use in IC for skeet, clays break easy and move kind fast. I use an O/U for everything (clay or bird). On birds, my 1st shot is IC and my follow shot is IMP. That's "generally speaking" with the theory being the birds escaping that 1st shot are always headed away, not closer. Might need a more aggressive pattern on the 2nd or if I have to take a further shot based on their behavior, I'll switch to the IMP because I need to. Even more likely on late season Mallards. Or...if they just aren't working close and a "pass" shot is what I'll be taking. I have options with the only downside being if I take a double up close that IMP usually tears up a little more meat. If one bird is a broke wing crip, I don't want an IC into the decoys either, the tighter pattern might save a decoy full of holes.
Either way, it's why "it depends" on where you're hunting and what type of ducks. If I was woody hunting it would be IC/IC because they're harder to hit, are normally low light and they're small birds. If I'm hunting a late season Mallard on an unfrozen creek and pass shooting their flying that traffic pattern, probably IC/IMP. If I'm hunting spooked Mallards from a field blind probably IMP/IMP.
My preference isn't just O/U based, when I shot a Beretta Silver Mallard, my shells were stacked IC/IMP/IMP for most of the same reasons. Same for Pheasant (which is even more applicable)
Advice right or wrong, it sounds like you shoot more clays than birds. That means you should now think harder about chokes.