Nice Car. Okay so for what it's worth, here is my opinion.
Your 2007 S-Class (221) calls for an oil and filter change (Service 3) every 13,000 miles OR 1 year. Well, I personally, would go for the 6,500 miles or 1 year. (Actually I change oil and filter every 5,000 miles on all cars religiously). That's up to you.
As for the oil. In the Mercedes Benz "Service Products" pamphlet, for your 2007 S-Class there is NO gray area. Mercedes clearly specifies and recommends you use oil that meets their 229.5 spec. This is what they list:
Mobil 1 European Car Formula 0W40
Castrol Syntec European Formula 0W30 (German Castrol)
Penzoil European Formula Ultra 5W30
Quaker State European Formula Ultra 5W30
ELF (Total Quartz Energy) Excellium 5W30
and that's it.
Basically, the most important thing to remember, is that Mercedes and BMW both require HIGH VISCOSITY, HIGH TEMP, HIGH SHEAR Oils. Thus the 229.5 and BMW LL-01 Specs.
I am sure there are many qualified individuals who can quote you all the minimums and maximums that make an oil meet that spec. (229.5)
I looked up the Shaeffer Oil 5W40 Supreme 9000 Data Sheet, and they do say that it meets MB 229.5 Specs and a myriad of others. According to what they claim, I would definately say it is a HIGH Temp HIGH Sheer HIGH Viscosity Oil. For all climate Mercedes recommends the following grades 0W30, 5W30, 0W40, 5W40, & 5W50. So your Schaeffer Oil falls in that recommendation. From what I see, the oil you have is primarilly for Diesel Engine use. (Hope I dont start a war in this thread with that statement)
I personally use the Mobil 1 0W40 in both the Mercedes and the German Castrol 0W30 in the BMW. All UOA's look great.
If I were to keep it simple, I would recommend Mobil 1 0W40 and definately the "Fleece" OE (Mercedes Benz) filter and you are good to go.
Hope this helped.