JBL L300 - true myth?


I'd like to ask if some can write his opinion on this speakers,I had a chance to listen and recommened .
I understand they working great with powerfull tube amp...especially with Mcintosh -is that true?
it's look the components are really good Alnico drivers special tweeters,horns...but woofers made of carton?is that a problem with today standards?
Is the old fashion crossover need upgrade ?

Thanks
scubidubi
Drop in replacement = JBL 2216nd. It blows away the original 2231 or 2235 hands down! 
I didn't know that they were Nelson Pass' favorite speaker.  Interesting because when I worked in the studios, we used to joke that the JBL 4311's were so bad that if you got the mix sounding good on them, it would sound great anywhere.  So maybe that's why Pass makes such good-sounding amps.