I have a Louisiana Grills kamado that I picked up at Costco for something like $499 (usually shows $100 more online).
It's unassembled and needs 2 guys to put it into the stand, but it's not difficult other than the dimensions making it basically impossible for one guy to drop it into its cradle alone. If you're putting it into a built-in, you may get away with it.

FIL has a BGE at home and out at the camp, so I've cooked on it quite a bit. The cap for airflow control is much nicer on a BGE, but it's a pit and not a piece of furniture, and it works fine. I don't get too many flare ups on long low-and-slow cooks, and it holds a temperature for quite a while without adjustment.
When I got it, I tested (without actual food) how long it would take to burn a full charcoal load. I had it left on ~220F and 24h later still had ~20% of the coals left. When i opened the vents, I could still flare it up for pizza temps.

Mine is ~22" cooking surface. They don't make other sizes that I'm aware of. The grill sits a little on the high side of the fire box, and a large brisket, I think around 18lbs off the shelf, took up every bit of space inside making it difficult to close the lid. The extra 2" on a BGE and sort of milder pitch on the roof may have made it easier. I should probably just measure these things and not worry about actually trimming meat in the future though, more realistically.

Cooking and sealing, I really give them a tie.

Accessories? You want a BGE. I haven't looked for a cast iron grill to fit mine, but FIL swears I need it. I'm plenty happy with the stainless one that it came with.

Shelves on the side of mine are a well-made, thick plastic. They're neither wonderful not bad. I would probably prefer bamboo on the nicer pits, but these are solid enough and haven't tried to melt even after putting the fire poker on them. This is really the other thing that looks nicer on a BGE that probably functions a bit better.

But for about 1/2 the price, I can deal with functional rather than exceptional cap vents and shelves.

Oddly enough, there's no link on the Costco site right now (they move products to unfindable once they are not available online) but am pretty sure I've seen it in the last month in store. Here's the Home Depot version which actually has stainless (appearing) stand and cap with bamboo shelves. It is a bit more expensive than the one I own (which is a navy blue ceramic) LINK

Also worth mentioning:
Icon Grills. You'll pay ~BGE price, but it's a company that makes fairly comparable accessories. I haven't used one, but I've seen them. Some of them have fairly girly colors and look a bit flashy for my liking, but the "control" box is something I think I would like. They have an insert for a fire starter which I think would make a big difference (lighting 8-10" flat on the bottom vs a column would be nicer than mine), but if you use a "blow-dryer" type starter it wouldn't be that advantageous. But it also allows for a propane insert which could be a cool feature. Never used it or seen it used in person, but it seems pretty useful if you would ever use it.

This post was edited on 7/27/20 at 9:04 am