An aluminum vehicle saves you fuel money every day/time you drive it by hauling less weight around. Also less weight to stop, so slightly shorter stopping distance. Might save you a fender bender.
Yes, repair may cost slightly more to your insurance company IF you bend/wreck it, so insurance likely will be just a tad bit higher, but the insurance companies seem to be standing pat waiting to see how the numbers settle out.
I see more gain than pain, but that is just opinion....and we all know what that is worth. Lol