I can agree with you on the documentation Joe. I recommend viewing the numerous videos Lionel CS has put out over the years as well as what other forum members have done.
In the end, once the locomotive is given an I.D.#, the meat and potatoes of the Legacy handheld are your everyday train functions. Throttle ,brake, whistle and bell.
The Legacy handheld has one big advantage over DCC and DCS for that matter. All of the main train functions can be accessed without ever actually looking at the handheld due to the tactile feel of the different controls.
Compared to a traditional transformer, it may seem complicated. Its really a matter of getting familiar with it, and as I said earlier. Its no more difficult than logging on to this forum.
I had some headaches before I could figure out how upload pictures and video onto this forum. After some time learning, it became easy.
If all else fails. You post your question on the forum, and get your answer just as you did. There is no manual with enough pages to contain all of the information available on this forum.
Funny thing though. You already knew how to work your Legacy system a month ago.....you just forgot