[N0sferatu]

I'm doing some homework looking around and I'm undecided on which model to go with.  I know the Denon I currently own was basically a rebranded Fostex headphone.  My DAC/AMP is an Audio-GD FUN hooked into a desktop PC.  I already have an open backed headphone when I want a different sound (Sennheiser HD600) so a new Fostex would be a swap out of my Denon AH-D7000.  I'm thinking of throwing them up for sale so if anyone's interested shoot me a PM they're in spectacular condition and I'm the original owner who bought them new.  
 
Anyways...this was my take from the homework I've done...
 
Massdrop TH-X00 - Great bang for your buck, appears to be a modded TH-600 from the factory, less bass, more mids, softer highs
Foxtex TH-600 - Not really interested in as the TH-X00 is a better deal and it's inferior to the TH-900
Fostex TH-900 - Looks like a closer comparison to the Denon AH-D7000, however sharp highs 
Tostex TH-900 mk2 - still doing homework on but how much better/different is this from the TH900 other than the detatchable cable?
 
For my ears when it comes to the "sharp highs", I own a pair of Monitor Audio Platinum speakers for our movie room.  It utilizes a ribbon tweeter that's extremely detailed.  To some ears it can be fatiguing.  It doesn't bother me but is this the similar type of sharp highs people are talking about on the Fostex units?  In general, I haven't had the itch to upgrade a set of headphones in over FIVE YEARS!!!  My two headphone combo with the amp/dac has been my workhorse.  I currently use my headphones every day on my workstation at home so price is not a concern to me.  At the end of the day, even what I paid for the D7000, I got my money's worth with the number of hours and years of enjoyment I've had with them.  
 
Do I drop a bomb and grab the TH900MK2?  
Is the TH-X00 a downgrade or side step from the D7000 and therefore a waste of money/time?
Is the TH900 worthy as a used pair over buying a new or used TH900MK2?
 
I'm looking for some real world feedback beyond reviews I've been reading/watching.  Thanks guys!  

 

[Oregonian]

Hey bud - got your link to this thread so here's my take. 
 
I'm 55 years old so though my hearing is very good (get tested yearly through work and have for 15 years) I'm not a "golden ears" who can tell if a mosquito farted across the room.............nor can I honestly say the TH-900 is better than my LA7000.  Had them both side by side, both modded equally at the time (Lawton damping, etc) and to my ears I actually preferred the Denon which may be due to the deeper cups I put on it.  For the additional $ going up from the Denon to the TH900 I don't see the value either way - but everyone's ears are different, etc.  The Denon and the Fostex are so close in sound I think you might be disappointed but that's just my experience. 
 
If anything, keep the Denon (a classic collector's piece now) and try another headphone signature.