The interesting part is that a man for whom money is no object - and who is also a professional musician - felt no need to upgrade his 40- 50 year old MC2105.
*According to the Mc book, Howard Hughes ran an MC2505 with a pair of Altec 7 in his personal "home theater" system while holed up in a Las Vegas hotel. Was said to be fond of playing to ear splitting levels, much to the anger of the other guests.
I used a MC2505 for 35 years with my Altec Valencias which are the smaller version of the A-7's. Still have the 2505. It alternated running the horns on the Vals with the 275 & 2125. I once measured the SPL @ 10' using the 2505 and it was 112db @ 12 watts. More than enough for those sitting closer.