Jadis amps and pre-amps still competitive?

How does Jadis amps (Defy7, JA 200, ect.) and pre-amps (JPL MK2, 80 MC), compare with the more popular amps of today from VTL, LAMM, and Audio Research. You don't hear much about them anymore. I remember that they were highly regarded when Mr. Victor Goldstein was the importer.
The Jadis 80 monoblocks set up correctly with right speakers and cabling are simply magical wish I could afford them.

Is there any truth to the comment above about Jadis preamp NEEDING to be used with Jadis amps only?

They don't NEED to be used together, although they do have an undeniable house sound.  I found my JP200 to work extremely well for years with my Lamm ML 1.1s, and I'm sure they would also mate well with my VAC amplifier (my JA80s sounded really good when I had a VAC preamp in the system).