Let's have it then: what is great about your "pellet grill"?
How about safety? grilling/smoking usually requires someone be nearby in case something goes wrong.
For a hot tasty brisket that was cooked 14 hours I go to a BBQ joint. Perhaps the BBQ joint uses a pellet grill (or will soon)!
A high quality BBQ joint may have trained staff feeding their BBQs post-oak and checking in throughout the day for top-notch BBQ - and you'll pay for that attention. But can you get an A-/B+ brisket out of a pellet smoker in your back yard? Absolutely.