It’s clear, thanks. I just wonder if we can say TAD amplification is better with TAD speakers than Vitus, at same product line level. Perhaps hard to objectively assess as it’s in the eye of the beholder.
I don't know Vitus + TAD so can't help to assess the differences but I can share my experience with my TAD speakers (CR1tx & ME1) in 2 systems with 2 different setups.
The Me1 are driven by a DartZeel integrated amp (CTH-8550) and there is enough power for a small room (20/25m2) with 330 watts RMS @4Ω. Sound is fast, quite dynamic, detailed and highly musical with a slight but beautiful coloration. Very good synergy between those 2 brands on my opinion. Simple and strait-forward setup. I love it.
The CR1tx are driven by 2 TAD M1000 (in bi-amping) which are highly neutral, not cold at all, super fast and detailed. Preamp is also TAD (C600) so no synergy problems. The M2500 are now discontinued and replaced by the M1000 which are more versatile when you want to bi-amp your system.
My take is that the M1000 (500W @4Ω) will perform at the level of your preamp - they have an input gain Gain of 29.5 dB like all the TAD Power Amps so it's important to find the right preamp partner (symmetric and Gain around 12dB like TAD preamp).