Pressurized oil systems always win in my book compared to splash lubricated systems. The oil has to "do" less work. With splash lubricant, that little amount of oil that is thrown out of the pan has to perform a lot of work, while the rest of the oil in the pan does nothing. A system pushing oil around means that more oil is seeing duty to carry heat off and limiting wear.
Onan or another company would make a killing in the RV genset market by making an inverter generator that is coupled with a decent sized battery, and having the generator run on something similar to eco-throttle. If a large load hits, the battery would carry it (like the Yamaha 3000iSEB's mechanism) for a short time until the generator is up to speed. The result would be a nice, quiet, economical genset.