If you can wait a couple of days, I should be getting my 13's back and I'll be able to do a much more detailed A/B comparison.
To be completely forthcoming, I originally purchased a set of 5's after meeting with Jerry Harvey and demoing the 5's, 7's and 13's. During that evaluation, I was very happy with the 5's. I thought the 7's were a bit too boomy and the 13's more neutral. But truly, they were all very musical, just slightly different signatures. Also, I really did not want to spend $1100 and thought that the for $400, the 5's were an absolute steal. Like I've said, they absolutely didn't sound like they were $700 less. More like $200 less. So I went ahead and purchased the 5's.
And I've been incredibly happy with them. I've used them on gigs where I've played keyboards, gigs where I've mixed front of house, at the gym as well as extended and casual listening. There has not been one minute or one song or genre that I haven't been thrilled with them. Read that last sentence again.
Then I spent too much time reading through the JH-13 thread...
Based on the raves and raves of nearly everyone, I truly wondered if I'd lost my mind when I demoed the 13's alongside the 5's. There was no way in my mind that the 13's were THAT much better. So after reading, yes...the entire thread...I found a pair of 13's for sale on the forum at a pretty low price that I could justify it to myself to purchase them.
When they arrived, they obviously didn't fit my ears, but thankfully were much smaller than my own so I fashioned some foam tips to create a reasonable seal and try them out.
As I've said before, there were 2 obvious differences. First, the low end went much lower on the 13's. Not to say that the 5's don't have nice low end, but the 13's go ALL THE WAY down. If I didn't A/B them, I wouldn't have noticed the difference easily. Second, the 13's high end extended out a bit further, but I definitely noticed what I would call a noticeable peak at 7k or so. Sure, it could have been fit issues, but I don't know. I listened to them several times going back and forth before I once again came to my conclusion that the 5's are an absolute steal, but then again, I didn't play any gigs or do any extended listening to the 13's because they obviously didn't fit properly.
I sent the 13's to Fisher Hearing last week along with my 5's with instructions to copy the fit of the 5's but copy every other possible detail from the 13's, hoping that I will end up with something along the lines of 90-95% 13's. I frankly doubt that the fine folks at Fisher know what Jerry does to tune his earpieces, but I do have confidence in them and they've been very patient to minimize my fears.
If anyone is interested, I'll give a full report when they arrive.