Tidal vs ATC

kanji is #1 audioprofessor .Period. 

Big active ATCs are awesome speakers.  I haven't heard Tidal.  In my opinion you should consider having a couple of pairs.  One pair that excels at big dynamics and that you can play loudly, and another pair that excels at reproducing acoustic music that isn't extremely loud and doesn't have massive amounts of very low bass.  That's what I ended up doing and I couldn't be happier with how it turned out.  I've got a pair of active ATC 110s that I can crank up without any hint of strain or distortion.  I've got another pair of Thiel 3.7s in another system and they excel at acoustic music.  Imaging is incredible and the presentation is incredibly natural.  The Thiels are clear winners at the things they do best but can't hope to compete with the ATCs in the areas they excel in.  And I didn't spend a fortune on either pair, got both pairs for 12k total.  

They are all obviously very good though for a significant cost. The end sound will depend on the whole setup not just the speakers of course so take all that into consideration. 

Everyone’s ears and preferences are different but at least a practical approach can be applied to matching gear and integrating that into the space in which it will be used. In the powered ATC case the amp speaker integration has been addressed by pros so that’s one less thing to have to address.

kanji is #1 audioprofessor .Period.

I would agree with that. Thankyou. 

For your room, given your equipment and MY taste*, go for the ATC 150 ACTIVE or you’ll be spending unnecessary time & money trying to drive them properly. The Agoria are excellent speakers but the ATCs will give you the excitement of classical, the immediacy of rock, and the beat (?) of techno, in one package. The 300s are too big for your room, I think.
*obviously: it's objective only to the extent of my own preferences!:)