Almost two months ago, I was reprogramming my BCD996XT for a new purpose, and I was amazed at the limitations on number of channels, text tag limits, TG limits, and the like.
The point? You never realize how much better the x36 models are until you are put into the situation of having to go back to older models. Yes, they are absolutely worth it. In addition to the above limits being practically gone, you have the Department/Site Quick Keys and Replay/Recording features - two of my most-used features, and some I miss on the older models. You also have the great text tags that show SO much more than the older models.
Don't get me wrong - the older models are still excellent, but they have limitations that you don't have on the x36 models. About the only feature I miss from the 396XT is the size. The 436 is much larger - mostly due to the screen size, I think.