Unfortunately I can only echo BadgerRivFan`s sentiments. I`ve not used the McKees version, but I`m a fan of the Griot`s.
I`ll often use it as a drying aid after a wash, and it`s my go to exterior window cleaner. Super easy to use (apply liberally, clean with one MF, allow to flash while doing the other windows, buff right off with a fresh PFM. Even works great in the winter when the garage is 3_°).
I can compare it to Wolfgang Uber. Uber probably has the edge in regards to gloss, but I like the Griot`s better for staying clean after use, plus general ease of use.
Does McKees offer little 4oz sizes so you could sample it?