I can see why many people would not like classic chambers. They can be VERY thick and heavy sounding. Plates would probably suit them more, but even these can be muddying and complex compared to many digiverbs.
But, the quality of a chamber is obvious when you hear it; literally MILLIONS of reflections bouncing around, with Doppler effects and surface reflections off every surface level. Like a drum room mic - when the quality is good, it does enhance the musical quality of the source sound. But when it's bad, it just mucks things up. Studios with existing chambers (usually built in the 1950's or 60's) still use them as main reverbs on a lot of things.
Every time I'm at Capitol, we use their chambers - all of which sound quite different. On the '60's and '70's, they USED to have a phone line you could hire for a certain length of time - you'd send your mix over the line to Capitol and they'd send it into their famous chambers. They would return the chamber sound back on another phone line! I think with high speed WWW, they should offer this service again....!