They are diff coolers not engine oil coolers.

 

Larger baffled oil pan benefits, that I can see, are that it can take more heat away from the engine than a stock one before overheating because of its larger volume of oil, and oil will not wash away from the pick up under strong g forces because of it's baffles. A motor with an larger oil pan can still overheat, it will just take longer than a stock one because it has more oil to heat up. The cooling fins (if it has any, not all do) are generally not large enough to actually transfer enough of the oils heat to the outside air, cooling the oil and equalising the heat the engine is producing as you thrash it. Obviously this will depend on your engine setup and how hard and long you trash it but if we are talking about overheating the engine we can assume your donig it pretty well. While an oil cooler with its much larger surface area in direct air flow can actually cool the oil once it’s taken the heat away from the engine preventing it from overheating.

 

Oh well..., still looks crazy nonetheless...

 

They do look cool, i was at my mechanics this morning who has a race 350z with a massive custom diff, along with a host of other very cool modifications