I ran the Omni subs with SEAS L26RO4Y 10" for a couple of months while I refurbished the proper dipole H-Frame boxes (see photos). Bass was powerful and tight. I didn't bother with any EQ for the trial, just driven straight off the 120Hz LP output into 60W/channel LM3886 chip amps. I did notice the omnis excited lower room modes that were not present with the dipole bass, but these could be reduced with proper EQ and perhaps room treatment.
I can't give a real comparison with original LXminis because I've never heard them. My own LXmini versions are all with 8" bass drive units instead of SL's 5", and also I wasn't happy with only the SEAS FU10RB by itself, so I always crossed them with an additional tweeter at either 5.8kHz or 7kHz. My LXminis do fall short compared to the awesome transparency and dynamics of the open baffle LX521.4 version, even though they are still mighty fine in their own right.
I did tidy up the wiring of the 3 top LX521.4 drivers, which I now suspend from the ceiling above the H-Frame boxes for improved isolation. ps the A500 amplifier is just for its heatsink case, actually inside are 4xLM4780 2 channel chip amps which each parellel drive its own 4ohm bass unit. Enclosure below them is their 1000VA 24-0-24V trafo.
Attachments
A closed box gives the best Q factor and is my favorite.. never liked the somewhat re verbing / resonance BR ported speakers which disturbs the low mid-range. TL also is great as well but mainly below 40 Hz.