I also searching real feedback aboout ETCR007AD, only what I found:
dot_bob 4 months ago
I picked up a ETCR007AD from aliexpress a year ago and it is pretty noisy just like the OWON in this video. Not worth buying in my opinion. I cracked it open and the PCB is pretty sad, missing more than 75% of the components and the two lone IC's that are populated have the ID markings ground off.
Yes, The hantek is really the only of the three that seems to work properly. The ETCR007AD I have is too noisy to use as a trigger source in addition it doesn't meet the advertised frequency spec of 100Khz, it's more like 8Khz.