I never counted it up, but the main HE-500 thread here probably has more posts by me than anyone else over past 3 years or so. I'm real interested in them - like the mods of which there are many, other commentary, and of course people interested in the 500 tend to congregate there. It certainly can warp ones view of the entire headphone universe - but after being a salesman, investor, builder, etc. in audio for over 50 years, and owning/demoing thousands of products - I like what I like.
I know this - if the HFM community puts out a bad opinion of them, led by HE-500 fans, it will chill the sales a good deal. People like the 6XX so that worked out, 4XX has worked out. xx not so much - primarily because either the HEX v2 and Ananda are better. I've got a very modded and EQ'd out pair of 500's, it might be unfair for me to go after the 5XX, unfair if I'm predisposed to a POV. I mean HFM is a very wise company in terms of business. If the 5XX is better than Arya, Ananda, and Sundara - then why so cheap? If its a REAL HFM can, why not bypass Drop? No, I'm pretty sure what it is, a nice engineering move for a small potent magnet - but not ready to mess with changing established products, so they took the bucket load of requests at Drop for the 500 (I know, I droped a few off myself), and here we go. Big hit - the 400 and Sundara go in for refits in 5-6 months using much of the technology. I've been expecting new revs for the Ananda and Arya - maybe some of the technology squeeks into those. Not many dull moments watching HFM and wondering whats next.
If your within 90 minutes of Lowell MA could lend you mine.