Shock/Diff oils

[knighthawk]

Ok chaps,

Think this has been asked but please excuse me

I normally run CoreRC Oils in all my cars, Schumacher, AE, Tamiya in on road and off road

Now I don't think I've had an issue but I get many many comments when I get my oil's out saying why are you running that crap

So what are peoples thoughts
Is there a real noticeable difference in the oils, Core - AE - Xray etc
Or is it just racers promoting what they run as the best ??

Cheers for your thoughts