I am a itching to find a mod to work on. So why not replace the stock oil/water cooler with an air cool. Do I need it? No. However I believe it is an slight improvement over the stock unit. With limited space I was given, I have to choose the most compact unit. It is a comprised between the cooler and the radiator. I don't want to have a bigger unit and blocking off the rad completely.
The adaptor from ZZP work perfectly as expected.

 

That's pretty cool, but more rows would be cooler

Oil-to-Water is pretty efficient in general and in theory, and helps the oil get up to temp quicker (coolant gets up the temp faster than oil), the downside though would be it would run the oil hotter than the coolant during high duty cycles since the already hot coolant can't pull as much heat out where air temp would be ~100F colder than coolant. I put a 19-row on my LE5 setup behind a 180° oil thermostat valve that will bypass the 19-row when cold, and I recently installed a mini spal fan behind it with a 190° thermostatic switch.

 

Good job. Your setup is ideal however the limited space I have and not wanting to block the rad, this is a compromise. Getting oil up to proper temp would be a challenge but I don't drive it during the winter months. And I do warm up my engine during the summer before heading off.