I've heard various OHMs over 30 years and currently own 2 pair.
I've also heard mbl 111s.
The technology is totally different. mbls are fully omni-directional and require more distance from walls to sound best. OHMs are largely omnidirectional but not fully and can go closer to walls.
Both owning largely omnidirectional radiation patterns, they tend to image and do sound stage similarly at least in the area in front of the speakers.
Tonal balance/timbre is noticeably different but I have never heard both on the same system so some of this may be due to different systems behind them.
Dynamics are good with both.
OHMs start at $1000. Small mbls start at $12000 or so I believe. mbl 111s list for over $30,000.
mbl 101s ($60000+) do low end dynamics better than mbl 111s I am told probably resulting from the unique bass driver technologies used on those.
"Are Ohm Walsh Speakers the Poor Man's MBLs?"
I'd say draw your own conclusions on that.
You may not see very many poor men with mbl, or German Physiks. Probably not many with OHMs either.
The big OHM f-5 series 3 in my system were a decent stretch for me and the most expensive speaks I've ever owned.
Westborn, have you ever heard Dynaudios? Do they sound muddy or plastic-y to you? I run Dyns concurrently with OHMs in different rooms off the same system and other than greater authority in the low end and the omni design, the OHMs sound very similar to the Dyns overall.