Pellet grill summary:
They don't replace a good gas grill because they don't get hot enough to sear. Most foods that applies to are better cooked on a flat top/skillet anyway.
They aren't a good smoker because they kinda blend direct and indirect heat, and have a convection effect that dries things out without a foil crutch.
They are more convenient than a wood/coal smoker and I don't hesitate to fire mine up when I am pinched for time or feeling lazy.
I am about 5 months into owning a GMG Daniel Boone EZ Bake Oven. Overall I do like it but it's not the end all be all of grills. It's about what I expected going in expectation management is everything in life.
It's a jack of some trades, master of none...well maybe ease of use. It smokes kinda, but not really. Adequate for home results...again, expectation management, but it's not top notch BBQ by any means. Not knocking anyones pride just my opinion.
It doesn't really do direct heat, doesn't sear at all, but it grills at midrange temps pretty nicely while adding a dainty wisp of smoke flavor. I wouldn't even think of doing a steak or burger on it but YMMV as far as what you expect out of those foods. It does chicken pretty well. Has hot and cold spots, like most any grill at that price point, but is an added hassle for larger batches of food.
Brand differentiation in my perspective, pick one. Pellet grill is a pellet grill, it's pretty much a ford vs. chevy issue. The different add ons and peripheral features there are some differences and the pizza oven was why I went with GMG.
My favorite part of it is probably the pizza attachment and even that is a bit finicky with temp, definitely need an infared temp gun and some micromanaging to get consistent results.
Another thing I really like is smoking fish at low temps without having to babysit the wood and airflow as much as I would on my drum smoker.
My only other complaint, and this is something I probably need to check with GMG CS with...last week I was doing a low and slow + sear at the end on some chicken thighs. I've done it probably a dozen times. Last week when I did that, I jacked the temp up, walked off for a few, and returned to the grill absolutely filled with this acrid black smoke. To me it pretty much ruined the chicken, I have a really sensitive taste for that. My wife and inlaws thought it was good somehow so I guess its just something I have a sensitive taste for. I was near the the of the bag of pellets so I think that dust in the bottom may have caused the issue.