To be honest, like the "Midnight Buffet" of cruising years past, the Grand Buffett was an anachronism that was due to be dropped. Yes, it was an incredible feast to look at, but we, like many we talked to, rarely participated, and more often than not watched vast volumes of uneaten food be taken back into the MDR at the end. While some of it MAY have made its way to the crew dining room, I suspect most of it went into the waste disposal system.
In the last two years we have sailed on Regent, Seabourn and Silversea, and with the exception of one of those lines, which one escapes me, and which only does it when Sunday is a sea day, Grand Buffets are a thing of the past.