ATC scm 19 vs ATC scm 20SL?

There are revealing speakers and there are revealing speakers. I find ATC to belong to the second category, wherein they not only reveal the weaknesses of a system or recording but also equally honestly reveal the strengths/goodness of the whole chain + recording. Hence to me it sounds like a very straightforward honest guy who is always willing to entertain with the right mixture of good and evil. If a tube preamp is required in a chain it is simply because

1. The tube preamp is adding more honesty to the system than the SS preamp in contention.

2. The rest of the chain is not honest enough in bringing out the beauty of the music hence needs help.

3. The system might be great but the room may not be good so instead of treating the room one opts for a softer sounding preamp.

Since a truly neutral system will do justice to all kinds of recording I would rather believe most SS preamps are on the drier side of the neutral.

All ATCs sound excellent on vocals. In fact in a blind test based just on vocals, it can be extremely difficult to differentiate between two ATCs. I have heard even their smallest SCM7 and even those had a very similar lifelike palpable vocal like my SCM40. Unlike many other brands all ATC speakers sound very similar with similar strengths and (weaknesses ?).