The issue with MET (and a bit of TWD) is that it can end up "woodchoppy" if you don't play or time the modes and multiballs properly. There's nothing worse than exiting the 2nd or 3rd CIU mode, with no multiballs close to starting and SnD ending wiping out your inserts. Or starting a multiball with CIU lit - that's just painfully inefficient play. Sometimes its luck based, sometimes its skill, but the best scores and gameplay come from the proper ordering of features and modes during play.
TWD suffers from this a bit if you end up struggling to get bloodbath, prison, WW multiballs staged properly, and Horde can definitely obstruct your progess towards LMS and Terminus (but its such a sweet mode who cares ). Again, with proper play these can be ordered effectively to keep the next goal always in reach but it doesn't always work that way.
I would contest that any game with 'depth' (not necessarily complexity) in the ruleset stands to suffer from 'woodchopping' if it depends on the players ability to progress modes and features in the correct (or most efficient) order - this isn't necessarily bad design imo as this is very different from the woodchopping from lazier game design like IJ4 or TAV. With MET or TWD you MIGHT chop wood, but on a good game you'll be cruising mode after mode multiball after multiball. Fire up IJ4 or TAV and there is no way to avoid the woodchop no matter how well you play.