JBL 4349 or Klipsch Cornwall IV

Check out Bob Crites’s “cornscala” speaker (now known simply as Crites speaker). Like the cornwalls they are a 3 way horn loaded speaker. I own a pair and imho are just fantastic. I run them with a vta st-120, and at 60w per channel they’ll blow you out of the room, very efficient. Only cons I can come up with is they don’t come with attractive veneers. Huge soundstage and very dynamic.

I owned the cornscala C version a few years ago. While it is a good speaker, it came with it's own set of problems. First, the crites xovers had to go and were replaced by an ALK version with adjustable taps for the mids. I also wrapped the midrange horn with dynamat. Even after all this the undoing of this speaker for me was the cabinet resonance in the mid bass. Not terrible, but undeniable in some material.

The bottom line is that although much more expensive, the CW IV is the better speaker.

I always thought that the JBL 100 was great for rock but not so great for classical, the reverse of what you write. As for the Cornwalls, according to the reviews I've read and heard, in addition to the views of audio sales people I spoke with, they are less than ideal for classical, better suited for rock and le jazz.

Thanks for all the input so far! 
I do understand that the Cornwall IVs are more critical when it comes to amplifier matching, given that my current amps are a Mark Levinson 432 and a “spare” Bryson 4B-SST, my setup is likely a much better fit for the JBLs. It does however seem that there are good amps suitable for Cornwall IVs that are relatively inexpensive. The question is though if a Mark Levinson amp, albeit seriously overpowered for high efficiency speakers, is a poor match with Cornwall IVs? 

Cornwall IV seems like a good match for me, the fact that there’s not a lot of really deep bass is no concern, it might even make it easier to integrate the speakers in my room. On the other hand, what I enjoyed about L100 classic was the physical impact they had, not sure if the Cornwall IVs will give that (although L100 classic don’t have deep bass either). I’m not really looking for a forgiving speaker, too many forgiving speakers are just plain dull even with the best material. On the other hand, there are revealing speakers that sound really good with a few recordings in a certain genre. It seems though that Cornwall IVs manage the balance nicely judging from your input above. 
As there’s no way I can demo Cornwall IVs at the moment I’ve come to the conclusion that I will accept the offer to try the 4349 in my home, if I like them, they stay. If I don’t like them (maybe too much mid bass or whatever), based on reviews and valuable input above, I feel confident enough to buy Cornwall IVs unheard. In this case I can start with the Mark Levinson amp and upgrade later. 

Well, for low volume listening I think you can't get much better than the Cornwall.  It sounds full and rich at low volumes.  The Cornwall sounds really great with low powered tube amps but your current amp will also work fine as well.