I didn't use any silicone spray on my bike. I wash it with just soap, degreaser on the chain and casette is applied using a toothbrush, and I lubricate the chain with a dropper. But the rotors are cleaned anyway.contamination as in some silicon from some spray. i used "mr sheen" on my bike, but i'm careful when i use it.
I see your point, I suppose it's true, but most companies to be competitive today use as many interchangeable parts as possible. It saves on research and manufacturing costs. Fun fact: Volvo (just one example) offers 4-5 diesel engines today with main engine being the same. They add parts to make it more powerful like turbo or supercharger. Sometimes the change is just in the engine control unit. You can just reprogram it and get the more powerful engine.in terms of displacement, while the MTB stuff does now have FM, i don't know if the pistons are machined the same internally for fluid displacement. chances are that they look the same, but who know without measuring them
Also Shimano does offer flat mount for MTB in SLX, XT and XTR range.
And they (including road ones) REAAAALY look the same
I imagine (I could be wrong) that they are all the same except for highest range XTR and dura-ace being of lighter material, but still dimension wise, the same.