Attrition Orbs Info
I've seen people in posts and comments talk about how much they love attrition orbs or my personal favorite combo, attrition orbs w/ kinetic tremors.
Keep in mind the frequency of orb creation is directly tied to your magazine size (and can be manipulated in some weird ways, see further below) and as such, if you run builds where orb creation is the fuel of your entire loop, maybe think about passing up a mag size mod or perk in exchange for better reload speed.
Some guns even abuse this relationship for crazier orb creation. One example most know of is the new area denial frame GL from Vesper's Host, where it can land a ridiculous amount of hits in relationship to it's magazine size. I am aware there is additional math going on per weapon type but my generalization is still largely accurate.
Another example of a possibly unintended interaction is how the undying reprisal weapons (ones with the vex-ish theme and leaves on them from Season of the Wish) have an origin trait that is very similar to rewind rounds but appears to function differently in that you can make orbs based on the refilled mag size instead of the weapons' actual mag size, increasing orb production as you refill the mag. Those guns have unfortunately been power crept a bit but are not bad choices at all.
One last thing to point out, if you want the most bang for your buck on ability regen, diversify your leg mods. Without breaking down the numbers (The D2 compendium does this excellently), three "orbs grant grenade energy" mods are less effective than even a single grenade energy mod paired with "orbs of restoration" which give 10% to the ability with the least charge, often being your desired and most used target ability.
The optimal leg mod combo mathematically is a copy of your most important ability regen mod, be it grenade, melee or class, paired with "orbs of restoration" for the 10% to whichever ability is lowest, then paired with absolution for 5% to each ability, granting a total of between 15% and 25% regen of your target ability per orb with an additional 5% to 15% regen of your other abilities on the side.
The above is of course affected by their chunk regen nerfs to specific abilities but that's a whole separate discussion.