I had a pre-Weber DUCANE that lasted many years and gave great service. When I bought it, I paid $15. extra for a "limited lifetime warranty". A few months before WEBER bought them out, DUCANE replaced (under this warranty) the firebox, manifold & burners, which had rusted out after many winters’ exposure, although covered. In other words, practically a whole new unit. WEBER, however, does not honor these original DUCANE warranties.
I’ve never owned a WEBER, but every time I’ve cooked on one I have been very happy. I think the burner bars are a much better way to distribute heat evenly than "lava" rocks.
I’ll also say that I think regular maintenance & care is the key to protecting your investment in your tools, be they culinary or otherwise.