Are you referring to the Masterbuilt Gravity Series and the new Char Griller offering?
If so, people that have them seem to love the results. Enough that the rave about them despite several issues they encountered with some poor parts. I have been intrigued by them too as you can have more control over smoke output and get to higher temps then pellet grills. However, it’s still an indirect convection grill and smoker much like a pellet grill.
A pellet grill is likely going to provide more reliability and likely last longer than products from the two companies making this style of gravity grills so far. The effort needed to cook a meal is probably going to be similar. Food results may have higher potential on the gravity grills though. I’m a big pellet grill fan, but think this new area has the potential to take a big slice out of the pellet market.
Edit: Lahawk1 snuck in while I was typing.