Scoring on Used Thiels here

The MBL omnis are peerless for disappearing and creating a 3 dimensional sonic image. Absolutely spooky, and ultimately the most realistic presentation within their frequency range

I've only heard MBLs once, at RMAF. They sounded good to my ears but nothing special. The room set-up was weird, tho', with the speakers along the long wall. Probably not optimal placement.

beetle one has to hear the MBLs set up properly to hear what prof is talking about. I’ve heard it in a showroom but never at a show.

The OHM F5 speakers I have in my main rig are my attempt to capture that at home. They do quite well for a fraction of the cost. Most peoples rooms, including mine, are limited compared to the dealer room I heard the ultimate mbl demo in, often in practice bringing mbl back closer to the pack mainly in terms of soundstage depth and 3-D holographic imaging.

The OHMs do probably have an edge on mbl in terms of coherency of the sound top to bottom, as do Thiels and a handful of others over the rest. I’m used to that very coherent sound top to bottom and tend to levitate to speakers that exceed in that area.

http://www.fredsoundofmusic.com/specials/pre-owned-components.html
U15040
THIELCS2.2FLOOR STANDING SPEAKER PAIR 999.00
95U15186
THIELCS3.6FLOOR STANDING SPEAKER PAIR-AS IS 899.95

If you live in the Northwest Fred's in Portland has these .

Thiel 3.6’s impedance drops below 3 Ohms.

A little off the track, but four or five Thiel 3.5's make a superb surround sound system.  the various locations tend to cancel out room resonances and without room correction allow their smooth bass to really make itself known.  You haven't heard an organ at home until you hear 16hz on such a system.

Another oft overlooked consideration .... the 3.5's equalizers serve as a buffer for high impedance tube preamps feeding low impedance solid state amp inputs.  This is particularly advantageous for me as I use ARC SP6a preamps into Outlaw M200 monoblocks (10k ohm inputs) to drive the system.