I'm not a mechanic but I can give a good but untested hypothesis.
Hypothesis #1. A larger oil filter on startup takes longer to pressurize than a smaller oil filter. Try blowing a baloon and blowing a hot air balloon with your mouth. (Don't try the latter)
Hypothesis #2. More filtering area does mean cleaner oil but I suspect that less filtering area is not a problem if you are doing 3k mile oil changes. Remember, that current oil filters are designed for 7500 miles.
Hypothesis #3. Small filter takes less of the pressure away from the engine while accelerating.
Cost aside. MB doesnt change something for no reason. Why would MB keep the SL R129 for 12 years. I hypothesize that MB saw these 300Es began to have tired oil pumps and to pressurize the engine oil's faster, they used smaller oil filters. Since, 300E's recommended oil is 20W50, they didn't have any room for using less viscosity. Probably, they couldnt make owners want to be putting in synthetic oil in an 1qt/1000 mile consuming engine. On my next oil change, Ill try the new filter out and post my comments. Can anyone post the pics of this new oil filter outside and looking through the bottom.