I’ve used the M54. It’s much the same as the CML Cali Common, which I use for most of my lagers now. I don’t think it’s a “real” lager yeast though gives good results when brewed at 18-19 degrees. I’ve no knowledge of the M84.
i started there mead one today.
i liked the performence. only put yeast with water to wake up and added a tiny bit of raisins after 10 minutes. gone made within another minutes
Used the M54 loads. In fact I got one on the go now with my Vienna lager. I'm no lager expert and could do lagering temps etc if I wanted to but I find the results perfectly acceptable.