I would like them at half the price.
Bosch seems to be the best deal (in this class) and get, what I believe is, similar filtration.
I am suspicious about the x2 holding capacity if solely based on media type. It is possible the add more media up to a point,ie. PureONE. Look teardowns on the M1 and true synthetic media (usually white fuzzy) filters like EaO, Fleetguard Stratpore, Royal Purple, or Baldwins with Syntec media. Then consider what a used filter looks like. The glass media would likely provide the 'depth' for holding more. M1 is claimed synth blend but the % is not likely large as glass is brittle and has a problem with bend radius requiring a mesh screen backing.