My old SA hubs don't need oiling every fifty miles and the expected lifespan of one of these is 50,000 miles whereas word on the street and the shop floor is that a hub like the Nexus 8 is going to buy the farm at about 10,000 miles and require far more service during it's rather short lifespan. Part of the Nexus issue is that their seals are poor and contaminants can enter the system and become suspended in the grease.

With the amount of miles I used to ride I could have worn out a Nexus in a year and know what it is like to log epic miles, and know what does and doesn't work.

In a system like a 3 piece bottom bracket or hub that are prone to contamination, the use for oil makes senses as it does not suspend these contaminants like grease can and every subsequent top up flushes out the bearings and races.

I have worked on thousands of bikes and do of course use good quality grease when I repack bearings as most bikes are not designed for oil service and most people just want to ride it and forget it. I don't see modern manufacturers designing internal hubs for oil bath lubrication although a friend of mine modded his new Shimano Nexus to use oil and it has continued run beautifully.

It was very problematic in the winter until he changed his lubrication to oil.

In tearing down my oilers I find that the bearings and races are very clean and in beautiful shape whereas greased bikes are often filthy and this trapped filth wears out bearing assemblies.