Speakers with warm treble and good bass

Jwglista,

Find a pair of Spendor S8e speakers and don't look back.

Give your Spatial Audio M3 Turbos a chance to break in and see what you think. I have the M3s (non-turbo) and have not had any listener fatigue whatsoever. I sold my Klipschorns after 17 years because of treble harshness that was causing fatigue, and bought the M3s after listening to most of the speakers you list and more. And to get the best of all worlds, I added a pair of Goldenear Forcefield 4 subs. Goldenear bass is sublime, and they've been a perfect match for the M3s, which have a warm, musical bass of their own. 

I own a pair of Vienna Acoustics Mahlers. They have the sound you are looking for. Dual 10" woofers on each speaker as well as two 7" mids and a 1.2" tweeter. You can find these used for good prices,but beware, the wood veneers tend to fade. Mine are gloss black and have not faded a bit. I am running a McIntosh MC452 amp, C52 preamp and a MPC1500 power conditioner. Sound is liquid smooth and has tremendous bass. No need for a sub here.  These were $13,000.00 new.
I have seen them for sale here for around $4500.00. 
if you can find a pair to listen to, I think you will love them.  They weigh something like 160 pounds each. 4 ohm, 91dB.  Big speaker. My room is 14' x 17' and they sound awesome, but will perform in a much bigger room too.  

Gamut M5 or M7. Best musical satisfying sound I ever experienced. I had owned 70% of the suggestion here.
Regards 

Alright there is a lot to respond to here.  First, I'll answer some of the questions that have been asked:

--Room Treatments
I am using acoustic panels from ATS Acoustics.  I have a total of 8 of them spread on the walls.  First reflection points have been taken into account.  

--Tubes in my Rouge
I have a range of tubes, but have been mainly using my Mullard new production EL34s for power.  For the input tube, I recently purchased a NOS Mullard CV4003 which is an excellent tube, best one I've found yet.  I've also tried the Brimar 12AU7, and another Mullard NOS 12AU7.  Other power tubes include Gold Lion KT 88 (good bass, good all-rounder tube), Tung Sol Kt 120 (not a fan, a bit too forward and aggressive), TAD KT88 (nothing special), SED Winged-C 6550 

--Soft dome vs. Metal Dome
I would tend to agree that in general, my ears agree more with soft dome tweeters.  However, the only exception to that rule that I have witnessed has been on the Totem speakers I auditioned.  They seemed very analytical to me.  Not bright and harsh like metal domes can tend to be, but it was still an uneasy sound IMO.

--My Spatial Audio M3 Turbo S
I've had the replacement pair for a week now, and have about 100 hours on them.  I am still not enjoying the sound.  They do several things very well, but I still get a certain aggressiveness from them.  It's possible that the high noise floor of the Rouge amp combined with the high sensitivity of the M3s is allowing some electrical noise to be amplified much greater than it would be in less efficient speakers.  Either way, it translates to a sound that my ears simply cannot settle into.  I am not going to start chasing my tail again on the amp search either.  

Next, I compiled a list of most of the speakers mentioned in the thread here.  Some have been omitted due to price, or other factors.  There are so many speakers here to try, but unfortunately the selection I have to listen to here in the Pittsburgh area is fairly limited.  That means it's all about taking the gamble and incurring more loss if things don't work out.  I am checking out my dealer this upcoming Saturday.  He does have Harbeth in stock, which I am curious to hear.  My main concern with those is the bass.  I've heard B&W before, and they weren't really my cup of tea; a bit too analytical.  I've also spent considerable time with a pair of Dali IKON 6.  My ears tend to have issues with ribbon tweeters.  I think it may be electrical noise that is reproduced too well by them.  They were pleasant speakers overall, but IMO leaned towards the analytical side.

--Monitor Audio
--Aerial Acoustics
----10t
--Dynaudio
--Harbeth
--Spendor
----S8e
--Soliloquy
--Vienna Acoustics
--Sonus Faber
----Liuto
--Rega
**--Proac
--PMC
--Alon Lotus SE
--Dali
--Avalon Acoustics Eidolon
--Tannoy
--Acoustic Energy AE109
--B&W
--Thiel