Enjoy your new speakers Oblgny. I have an old pair of the MMGs in storage. They started to delaminate that I fixed and a foil broke that I somehow repaired by soldering a wire across and holes were drilled into the wood edges so I could mount them on hinges off the stereo cabinet.
I feel sorry for my speakers. Living with me is tough. The new victims are the LRS Great revealing speakers and yes it seems the amps need warm up.
It would interesting to compare them again.
I should sell the MMGs but they are a bit of a mess.