My experience with what you and @TLS Guy
are saying is after I upgraded my subs to RBH when I got there reference version subs passive version I had 2 crown xti 6002's put out 2000 watts each channel into 4 ohms more into 2ohms.
I was so excited right? When I was running them with the crown and was adjusting there DSP I noticed in movies in my room about 15 below reference they were slamming. The subs themselves were so far below reference I couldn't even see the input lights turn on. I estimated I was probably using maybe 200 watts RMS probably 400 peaks
The crowns were just complete overkill. The fans were to loud anyway so I bought from my dealer RBH's sub amplifier which only puts out 500 watts RMS. I thought to myself why build these monster subs only to provide them with a 500 watt amp?
Once I had them hooked up level matched and set to the right eq setting eq 4 for the reference versions I understood why.
500 watts was more then enough beyond enough for my room with capable subs. I do feel that my main amplifiers do probably work either harder or just as hard with giving power to give me the midrange voices and dynamics for the rest of the system to match the subs