Barnes Expander MZ Sabots

Who uses them? Who likes them and why? Who doesn't like them and why? Picked up some 250 gr. to shoot out of my new omega. would you recommend a 100 or 150 pyrodex pellet load? (out of 777, so i had to substitute and season comes back in saturday) also what do you shoot in your omegas and what kind of groups do you get?

I'm not an expert, but i did stay in a Holiday Inn Express last night.