OO is my primary aeration method as well, simply because for the longest time I didn't have anything else. I have not done a split batch, so I'm only going by the attenuation numbers to prove to me that it's working. There could definitely be a difference in flavor (and I'm sure there is!) vs. traditional oxygenation, and to compound matters sometimes the yeast that is pitched is grown on a stir plate, so its getting a fair amount of oxygen right there. I'd love to do a comparison of OO vs. mix-stir, starting with fresh yeast, but I guess I'm just so darn lazy, and the fermenting fridge only holds one fermenter.
Since I switched over to the SP10 burner the kettle sits a bit lower to the ground, so there is a lot less foaming when I transfer to the fermenter. I have noticed these lagers take a good 48 hours to get going, one of them took 72 hours, which is longer than I remember. The very first beer had some sulfur, which could have also been caused by slightly underpitching since this yeast was grown on a stir plate and should have had plenty of oxygen. John Palmer made a comment on a recent podcast that said you could oxygenate by a stir plate alone, but I don't have exact numbers so I won't misquote him.
In the brewing industry, it seems that several brewers (New Belgium, de Struise) tried olive oil aeration but most or all of them gave it up for one reason or another. This would be pretty strong evidence that it does not provide everything that O2 does, or the flavor is somehow different. I'm not seeing a big detriment to the beers I'm making, so its hard for me to change what is working. But eventually I'd like to do some comparisons in the pursuit of better beer if I could kick this laziness!