Which Generator? Kohler or Generac

There have been many threads on this and other boards concerning the better of the two brands. But in my review of those threads, people always seemed to be discussing 12 to 20k air cooled models. I'm not looking at an air cooled unit in either brand. I'm between a 38k Kohler liquid cooled and a 38K Generac liquid cooled.

My concerns are build quality, parts availability, reliability, and ease of use. I've heard that Kohler tends to be better where build quality is concerned, but the difference is very slight to non-existent when you are discussing the liquid cooled models. Reliability, I'd think, goes hand in hand with build quality for both units, i.e. both are reliable. Regarding parts, I'd expect Generac to be more available given the larger number of dealers, but is this anyone else's experience? I'd expect all of the standby units are easy to use, but has anyone had good/bad experience with either brand's apps?

Any other thoughts are welcome and appreciated. Thanks in advance.

For the record, I recognize that these are standby systems and aren't made or designed to run for weeks without attention. For extended outages, such as in a storm scenario, I expect to power down the unit daily and check the oil, and change the oil every so-many hours. I also plan to have sufficient filters, oil, and spare parts handy to handle this myself, should I need too.