I haven’t tried European pears on them much, but they’re highly compatible with both apples and asian pears, with non precocious (typical) European pears you’ll get oversized trees, not just full sized, so it’s best for pickup precious varieties,get the early fruiting and get precious dwarfing, if your pears have any quince genes, they possibly won’t work, and there are some pears rumored to be quince crosses.
If in doubt you could use an Asian pear or Bartlett or almost any interstem. I’ll see if I can find the thread, but there’s a good thread about grafting wild Callery pears.
Here is my experience with 100% success for all varieties of apples and pears that I tried, some were not long tests as you can read there.