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