Weber's are the best looking. You can choose between either porcelain/ceramic grills or steel, both have their own pluses and negatives. Porcelain heats evenly but you won't get the grill marks that you would get using a steel grill. You also have to be careful to not scratch the porcelain, once you do it'll start chipping and you'll have to replace them, which are pretty expensive. Steel doesn't chip and they're way cheaper to replace. I prefer steel.
Where is the good prices on natural gas?
Something to think about when choosing between LP and NG.
Propane is hotter. It's one of the components of most natural gases and byproduct of refinement of crude petroleum. Propane heat output is about 2,500 BTU per cubic foot. Methane in its turn is the main constituent of natural gas and its heat output is less than half of propane's - 1,012 BTU per cubic foot.
So if you like to sear your steaks, LP is the way to go.
I would think that the fuel regulator would adjust and compensate for the difference in heat, would it not? I can't imagine my existing Weber would put out half the heat if it were a NG model.