I still don't understand what you are asking then. Is it whether alum hold up for bashing? Is it worth spending money on alum for bashing? If you are having problems breaking specific parts, then yeah--look for a metal option only for that part if you think it will solve that particular problem (or better yet determine if there is a design issue you can work around). I think you noted once your Savage is like three pounds heavier than stock, correct? What caused that? Were you breaking lots of parts? If not, think of how much more nimble it would be if you shed three pounds off it (which is a LOT for an rc vehicle).
The benefit in this kit is the tuning options, not the material, which can be argued is a liability. If you look at some of the most durable kits on the market...how many of them are saturated with alum parts? It's a marketing ploy. Like those alum a-arms. I even one saw an alum air-filter. Really? I imagine some poor chump just followed the leader and was told that it's needed. I imagine he popped it on, slowly rubbed his hands...fired up his engine drove around for a bit and thought "Damn I just wasted $15.00" ;-)
You noted you were looking for it to handle better at higher-speeds (completely understood as I've been working through that as well). Even then it's a generic statement, eh? Really not trying to be obtuse...just trying to understand your approach here. You know I'm not as savvy as others on here, but am happy to help with what I've learned (often the hard way).