Hey alot of posting here so I like to clarify my post.
The problem I see with your post is that your description is too good to be true....
While I agree these sound quite different than your typical T50RP mod, I would like to point out some things where I feel I should try to offer a counterpoint or correction because of your (in my opinion) too-good-to-be-true impressions (so please don't take it negatively).
"Once you get into high-end territory, all the headphones are good enough to satisfy you IMHO and it's more about finding the flavour that suits you (and your music) the best."
I have to agree on this...
I also have to agree, and concede that when I am optimistic about a can it tends to seem like its more than what it is,
Basically it was the qualities I tried to point out, I believe still holds true.
My intention was to describe the can's sound.
Also, I would put the slants in terms of pure musical enjoyment, with only the best I herd, because of the end resulting satisfaction that you get..
With Slants You don't feel like your missing anything,
While most top cans seem to excel at a few things so well,
that it stands out like a sore thumb. ..(hd800 soundstage; he6 dynamics; LCD3 bass)
In other words cohesive balance of the whole sonic image.
Another sonic point I like to mention Is that many top headphones don't have the sonic "height" (tallness) of an hd800, but this slant did come close more so than others..
Also I don't agree that a closed can is inherently a negative trait.
Ultrasones ed8 & sig pros are great examples.
So yes it is a closed can and no closed can will sound like open but this type of closed can portrays the sound where it uses this quality as its strengths.
The slant makes up for lack of uber soundstage by using its closed in potential to more clearly point out details or layers from its quiet deeeep background.
I still say soundstage similar size or larger than an AlphaDogs, which is no slouch at all.
I don't agree with some posters saying there is lack of ultimate detail because I believe it has to do with the amp.
My Oppo HA1 has alot power to give the slant which I believe helps imorove detail and bass quality.
Running them balanced with powet they simply scale up.
So to me I am not hearing boomyness, I hear more bass wich is of a slam type combined with body or thickness to it which reminded me of lcd.
I guess my post makes it seem that it has lcd bass so your correct it does not.
It has its own unique bass.
Again must point out the bass is unlike any of the other t50rp mods I have herd it is a satisfying organic type bass that is the top reason I could not believe it was a t50rp driver. .
Also I am not hearing any plastic sound at all,
which I have herd in lesser small cans..
What I hear is liquid and and my oppo HA-1 tends to be on the bright side in terms of signature.
I remember what "plastic sound " is,
I believe it is a treble/reverb quality that does that.
I also know with trebles,
Your sensitivity is highly dependent on your ear shape & ear canal shape.
Some people may be more sensitive.
I found the he400 &500 to be a bit agressive in that area while the he6 excelled untill the he560 came wich depending on what your preferences are, can be better,
as he560 lacks ultimate prat of he6 but gains soundstaging over the he6.
I would say you can't go wrong with these cans, FULLY MODDED ONLY..:
Hd800
He560
He6
Lcd2
But they also need to have also the equipment to make them shine.
The Slants "may not" be "better" than any above(!)...BUT,
they nevertheless manage to be in the same catagory ..why?
Because:
1- Slants also get Better with more power, just as resolving as any above as I am easily hearing details with more "presence" than usual in background details.
2- They're already moded.
3- Not as picky with equipment.
4- Have great sonic tonality balance with realism which easily places them in top can status on a musically satisfying level.
5- Have no "closed can" peer or equal,
(Edit) with very possible exception to competition of new tuned Vibro & Alpha Prime...
So in this view I can say my over optimistic post did have some merit.
AND your taming it down also had some merit (!) Lol
To balance this second positive post of mine...
THe biggest problem with the slants is price.(!)
The ZMF ViBRO gives more for money while being more musical to me than the AlphaDogs and with new tunning should be arguably similar level overall sonically to these Slants ...
Yet remains to be seen if a large sonic impression and realism is matching the level of Slants.
The Alpha Primes are about 300 more and arguably sonically superior...
It remains to be seen how much more it can surpass the vividness, slam amd impact I hearing on more power and balanced xlr out ..
So there you have it..