Curious. What hi end IEMs have you tried out? How long were you able to use them to come to a conclusion? Where you in a noisy environment with distractions?
Just looked up the XTZ. Looks pretty interesting. DSP to improve sound quality.
Interestingly enough a fellow headfier (someone who I definitely have confidence in) compared the SE5 to an open back LCD2. He mentioned the SE5 beats it by a nice margin in sound staging & treble quality.
As a reviewer, I own/owned a number of IEM's (pretty much the whole DUNU line, including the DN-2000J, a number of Shures, Savant etc.) and auditioned a number more (JH16's and a few others) for a decent amount of time. They were pretty much all in quiet rooms with summit-fi equipment I could never afford.
Have I tried many $1800 IEM's? No, not really - although I did try one or two, I forgot which ones they were, aside from the K10, which (again) really doesn't begin to compare to most open headphones I know of - even something like the HE400S. I noticed the post you mention about the LCD-2 vs SE5, and while I can't say anything regarding that specific comparison, it's pretty well-known around head-fi that IEM's and open-backs don't work together in comparisons - pretty much a taboo subject around here unfortunately. It's also important to note he was comparing the SE5 to the first version of LCD-2's; I don't know much about them but I think there have been a few much-needed revisions since. The LCD line also isn't exactly very neutral to begin with; an HD800 would be a better comparison.
And if I'm talking about the same post you are, we should also remember that was written 4 years ago, in 2012. Audio has come a long way since then.
I guess high end wasn't the right word - I'm thinking of $700 IEM's as my "high end", not $2000 ones. Still, the Savant was a joke in comparison to open-back's soundstage, presentation... pretty much everything. The DN-2000J, though fantastic for its price of an IEM, doesn't come close to even the K7XX either. It doesn't even begin to compare.
I'm pretty sure that's why we hear "tuning" a lot when it comes to IEM's, and almost never by high impedance open-backs. IEM's are often times 'tweaked' and 'tuned' since naturally in their small form it's nearly impossible to get a full, neutral, sound that doesn't come off as inaccurate. Most $1000-$1500 IEM's I've seen reviewed here go for the "fun" sound sig - even if that is a very coherent fun sound.
I have not seen a HD-800 in IEM form though - not even close. Even the new Shure electrostatic (forget the name atm) "sounds like an IEM" according to Jude.
I just don't get people who get something like the JH16's when something like the T90 + Aune X1S literally make a joke of it. Unless, of course, IEM's are the only option they have practically.