I own and enjoy my Sopra No2s. The top end is definitely lively and the tone will be unkind in an untreated room. I treated the ceiling and the sound came together very nicely. That point of reflection was the primary source of the overabundant top end.
I auditioned different amplification and along the way found that the Sopras play best with an amp that has a high damping factor. Forget tubes. Hegel amps have a very high damping factor and that's what I decided on. The base I'm getting is very pleasing and well controlled. (fair harbor statement, I have bass traps in both front wall corners)
If I was going to look at an alternate speaker I would consider the Wilson Sasha DAWs. Wilson just rolled out an updated version of the DAWs. The secondary market is flush with used DAWs and they are similar in price to new Sopra No2s. Good hunting and cheers.