Dino oil is fine with frequent changes. Just use 40 or 50 weight multi-viscosity variations and avoid any of the 30 weight stuff.
I've used Mobil 1 in my Mercedes cars for the last 18 years. I've used 15W-50 Mobil 1 in my '91 300E since the first oil change and that's what I'll keep on using. Since I do my own oil changes, cost isn't a factor for me.
BTW, it's my understanding that the 0W-40 oil now used in all Mercedes cars with the FSS system was originally developed for Porsche as the oil used in cars leaving the factory. When they first started using that oil it wasn't available in the US. I asked a Porsche owner what oil Porsche recommended as a replacement and was told it was 15W-50 Mobil 1.