+1 for cast iron grates and for rotisserie compatibility. While you're at it, a "rotisserie burner" is a clever feature (my grill has one on the back wall). If you want to make gyros or something, this means the heat comes from the back while the drippings go down into a pan or whatever. The pan doesn't need to sit in the fire.

As to brand and longevity, I ended up with a no-name model from Lowe's. I figure it will rust out or otherwise crap out in five years, after which I'll get another one. I looked at several much more expensive grills and wasn't very impressed with the differences. They're wider, but that's about it, yet the prices can be in the thousands of dollars. No thanks.

If I *really* need to grill more stuff at once, I'll go get a charcoal Webber or something else cheap.

(And for steak, I'd do that inside, where I could get a nice char with my cast iron skillet, and 18K BTU stovetop burner, and then transfer to the oven to finish it.)