jon,
No have never owned mbl but heard in demos on various occasions at dealers and shows.
I have owned OHM Walsh speakers for many years and these are still my go to speakers. They are radial designs that have a lot in common with mbl in regards to overall presentation but are much more affordable and designed to fit into most people’s rooms easier (closer placement to walls possible).
Most people including myself probably do not have the rooms needed to allow larger mbls to do their thing to the max. That and the cost make them a tough choice for many I would say. OHM Walsh speakers are a much more practical solution. Plus OHM is US based, has been around many years, and offer absolute top notch customer service in most every regard. TCO over time is much better with OHM I would expect, especially for US based customers.
I also suspect OHm Walsh is much easier to drive than most mbl speakers so easier to get the most out of them (which is a lot) with reasonably affordable good quality amplifiers available to most in the US.