I have 1999 year A3s with toroid I backplates. I could make 100WPC Atma-Spheres clip when I pushed them. I do love the way they sound. I have never gotten the VTLs to clip, and I’m surprised how good they are in tetrode mode. I thought they would be a big step down from the Atma-spheres but I am happy with them. If I compared MA-2s vs. the VTLs, it’s very possible I”d prefer the MA-2s but I wouldn’t know without a careful comparison. One option for me would be to update my soundlabs someday to be more efficient (to everyone: Is is PX panels or toroid II that helps more there?) and then compare the Atma-Spheres and VTLs since I still have the Atma-Spheres.
And, I agree with other posters that the Atma-Spheres are very reliable and easy to care for. More so than the VTLs. And also agree that Ralph Karsten is a wonderfully knowledgeable and communicative manufacturer.