I would expect more real opinions from the end users instead of a few re-sellers fighting here.
Tautech is, and rf-loop (I believe) was a re-seller for Siglent. Everybody else here is an end user without affiliation with any manufacturer, to my knowledge. If anybody does have a vested interest in any of the brands (beyond pride of ownership ;-), it would be the right thing to disclose that here.
I'll chime-in as a Siglent brand user as well. Being primarily exposed to/and having history with the A brands through my work, I had followed the lesser brand market with curiosity for a long time. I really hadn't taken them seriously nor spent much time considering them, however, seeing that many were moving to an embedded Linux architecture changed my mind.
I decided to outfit a "mini-lab" at home to investigate what some of these devices could offer and to see how they competed. I researched most of the brands discussed, and partially based on features/price/availability and partially just arbitrarily I chose to buy a suite of Siglent products. Frankly, for the price I was shocked at how much functionality they offered. While they weren't quite as polished as the A brands, and have some quirks/bugs, the response from all the technical support resources (here online as well as the US distributor) has been timely and appropriate.
I suspect that most users like myself in this market probably followed a similar path and have much more experience with one B brand than the others, so I can't make direct comparisons. What I can say is that I have not been disappointed in the equipment I selected. In fact, I've even purchased more units for my work office where I don't need critical top-of-the-line performance/accuracy/etc, but just need something that works and doesn't disappear from my desk.
I'll also add that the people on this forum, including tautech and rf-loop, have been extremely helpful and responsive and are a great resource no matter which brand you choose.