Well... i agree with you on the first part of your post, abou the changing trends but:
MZ's are literally no better than ANY other Generic Egyptian hookah
MZ in my experience are really good hookahs. I own one and it is my main rig for the last 5 years.
I would buy a Mya hookah over an MZ at this point in time ANYDAY!
I agree that myas have better construction over egyprtian rigs (including KM) but that doesnt mean they are better performers or more practical. Even after buying a mya colosus, egyptian rigs remain my favourite.
Other than that, i am a firm believer that any airtight rig with a big enough base, can perform the same. The reason i suggest mz rigs is that i've had good experience with them. i dont think any rig here gets it as bad as mine does... I travels with me wherever i go in a backpack with the stem haning out, knocked 100's of times over, i never take the water out after a session so it always has water in it.
5 years and it still works like the first day.