so I ll answqer this myself and maybe share some experience

I ended up getting the hitec hsb9370th servo as a steering for 1/8 buggy. it has tons of power, plenty fast for me. Its SILENT, I had futaba bls156 before, despite it being really quiet, this hitec is on another level - you hear no buzzing/humming even when you press against the servo horn. centering is great, finish of the case is very fancy too.
It is powered via 6V/3A Bec and experiences no brownout issues, I guess its fairly power efficient. It is also able to charge back your receiver battery while braking, for usage with BECs hitec provides a device - PAD - to consume the backflow current.
This device, for some weird reason, was not included in the package (acc to hitec, it should come with every brushless servo), so I had to dig around a bit, since Hitec specifically say, that unsupported BECs/ESCs will damage the servo due to this current (got same information from Futaba service - long story short - "use lipo or servo fries" ) and there should be a list on their web page of supported devices, but I did not find it anywhere.

I conntacted hobbywing and was told, that their speedos can run BL servos. So the servo is being used without the PAD and so far gives no issues, I ll see when tested longer the track. So far I am very surprised.

If someone is interested, here is a short video, it is not a review by any means, I ve just recorded it for my friend to see the servo..
https://www.youtube.com/watch?v=f8NcZzaZFQA