I don't find it boring at all - it's a great game. Just set up the difficulty to suit your skill.
I've played MBs setup too easy, and then it can get boring - this can pretty much happen with any game. In our league we have papa A players that have MB, and have had it for years. So no - it's only too easy if you set it up that way. It's a somewhat shallow game, so if you are only into deep rule sets, then it's not for you. It's one of the best games, most fun games ever IMO.

It may be more of a personal point of view, but I don't consider Monster Bash to be a Wizard Mode -> it's just a deeper multi-ball. Monsters of Rock could be thought of as a Wizard Mode I guess. I never think of getting Monsters of Rock as "I beat the game". I don't need a game to be "deep" to be fun or challenging. So while I like some Stern rule sets a lot, depth is NOT the key to a fun and challenging game. It seems like it is the key for many pinsiders, but not for me. For example, Fish Tales is simple, challenging and fun - but not deep. For many of the really great A players, it's better to have a game that is NOT a long player, with a deep ruleset. For example, we almost never play LOTR or TSPP (multiplayer) because it just takes too long! But MB setup hard and FT are fine.

To the OP - MB gets way more love than ACDC Premium at my house -> so I say go for it IMO.