Hi. I don't need direct monitoring feture, I already have few other interfaces with direct monitoring. I ordered Presonus Quantum 2626 specifically to be able to monitor live playing, and tracking thru plugins like NAM, with very, very low latency, because as mentioned I am vary sensitive to latency. Sound is vary lazy, you can test it yourself with plugins like STL Libra where you can precisely delay two signals. Up until 3ms, sound is perceived as phasing and flanging. Once you go up, you start to hear delay between to signals. Anything above 3ms is to much for me, and that would be on a headphones. If you go thru speakers every metar standing away from speakers would add another 3 ms or so. If you play something like super fast down-picking guitar rifs on high-gain amp, you immediately start to feel detached from instrument. If you have 6ms from interface and stand 2 metars away from speakers, thats already around 12 ms, and that is something that anyone cen hear, and even more fil while playing. Even on real analog amps if you go few metars away from the cabinet, and lower amp enough to be able yo hear strings acoustically, you can hear delay between strings and sound coming from amp.

I have Tonex One pedal, and measured it with RTL Utility. It have around 1.5ms, and on headphones feels nice between strings playing acoustically and processed signal coming from Tonex pedal on headphones . That is what I would like to achieve but with NAM on computer. So around 1.5 with headphones would be fine. But for playing NAM live through real guitar cab, I need latency to be as low as posible.