Getting a new gas grill today.

[Wayne LaBanca]

Searing is not needed. The key to juicy meats is resting, let it sit, off the grill, for 5 minutes after cooking.
Hamburgers: Don't press them with the spatula, this will dry them out. Yes it's fun but it makes for a bad burger.

Just pre-heat the grill and then cook, preferably with the lid closed. Keep your eyes on it thought, hamburgers tend to get engulfed in flame, just open the lid and move them away from the flame to calm them down.

I always cook on low heat, with the lid closed this is all you need. Higher heats are more for charcoaling with the lid open, I will do this to finish chicken breast with the skin on, etc... .

Alton Brown's "Good Eats" show has a couple episodes that cover searing (I believe this is the myth smashers episode) and on grilling.

Oh, one more thing, close the regulator on the tank when you are done, don't rely on the grill controls to completely shut down the gas flow.

[Poconos]

Just my own preference but when I was looking for a gas grill about 4 years ago, first time in maybe 15, found hardly any will handle lava rocks and I like them. Takes a little longer to get up to temp but I think they provide more even heat. Finally found one.
Al