Solid and lightweight product, but a bit bulky and concerns about ruggedness - Magpul Industries MBUS Front Flip-Up Back Up Sight Gen 2

I got the MBUS front and back flip up sights Gen 2 as part of an AR 10 build and I am pleased with the product overall. They are lightweight, though aluminum might be about the same weight, and appear very well made. I also like the flip up feature as most of the time I will keep these in the laid down position... they are just a back up for if the SHTF and my scope goes out. My only cons with the product is that they are almost all plastic which gives me concern about ruggedness, though I am not crawling through the woods with my rifle, and they are a bit bulky. The cost for the product, when considering it is mostly molded plastic, is a bit high too, but I can't believe how much the full metal sights cost...there is IMHO no reason that a single front or back sight made out of aluminum should cost over 100 dollars, so this Magpul MBUS becomes a better deal unless you are using your standard sights as the primary targeting mechanism.