Personally I can't say that your impressions are universally true based on my experiences Mr. Tennis. When I think of "hot" in planer/ribbon/electrostatic designs the first one that comes to mind is the original Martin Logan CLS from the mid 80's. Unfortunately I feel much of what I perceived as it being "hot" was the fact that there was so little low frequency information and it just didn't have a balanced presentation. I really didn't like it or the Sequel for that matter and because of those early experiences never though much of Martin Logan although I heard a few budget models years later where this impression wasn't the same.
So far as ribbons, I have listened to numerous Apogee models over the years and NEVER perceived the top to be hot. I would think if they did sound that way it could be a synergy issue with the amp maybe? A pair of Agogee Stages (2K retail at the time) still conjures up some of the best high frequency performance I've ever heard from any speaker at any price point. There was also a Clements speaker, can't remember the model number, that used a ribbon tweeter and it was not at all hot, actually I thought it was quite impressive how the tweeter blended with the dynamic drivers in that design.
