i've installed 5 er9 and 4 sensah 2x11 mech. for me, LTWOO > Sensah, any day of the week. The FD from Sensah is useless, i've had a Sensah RD die on me for no reason and Sensah told me to go F myself. Meanwhile, at least until now, my experience with ltwoo has been flawless. I'll be the 1st to start shitting on them if that changes, though.
People here keep saying erx has had problems. Afaik, the sleep issue was because of batteries with tabs instead of springs, that's fixed now, and SOME have complained about water ingress in the cable port of the RD, which you can seal with grease or liquid electric tape. Tracevelo literally submerged his egr and had no issues. I'm not aware of other issues?
And the er9/erx even has more functionality in the app than shimano; i dont get the hate.