Field coil dava cartridge

I have been hearing great things about the dava field coil cartridge with the tube power supply. I am only able to read a few reviews on them. The reviews seem all positive and the designer Darius seems to be a very approachable person . I would like to hear opinions on the strengths and weaknesses of the cartridge. Especially comparison with the Lyra atlas sl which is my current cartridge.

thanks in advance.