I have a dogbone, about as inexpensive and basic as it gets, good for small pack.
I have a lanksy mini-croc stick which I like due to the fact it has a wide area for the balde, which allows for different angles and edge work.
The sticks can also be removed and used by themselves, or placed in a slot side x side and used for hooks and points.
I've been pleased with it. it's a little larger than the dogbone, so wouldn't work in something as small as a PSK, on a keyring, or lanyard.
Some of the other pull through models have narrow slots, and you are confined to that angle, and that angle only.
In reality, anyone could just buy a single repalacement ceramic rod for any of the popular models (not too long) 4" or 5" would suffice, and it would do a fine job for most touch ups in the field.
For compactness and EDC the Dogbone gets the nod.