I'm a bit worried about your amp/dac inventory - it seems to be leaning towards dark sound (one amp is even called "DarkVoice").
Haha, well the DarkVoice is an OTL Tube amp used exclusively wilth my HD650s. The high output impedance will probably make the Takstars sound worse but don't knock the tubes because of it, they are nowhere dark or muddy used with the right cans.
With that said, I do prefer a more balanced sound. Recently I've tried a couple of Chinese budget IEMs that were really treble-heavy and it didn't sit right with me. Not that I'm overly sensitive to treble but that signature really over-shadowed everything else of what I was listening to.
Even iFi Micro ICAN SE, which is a SS amp, has the "TubeState" technology, which makes it sound like a tube amp
I wouldn't call the ICAN dark per se but then again, I have always considered "dark" to be more of a veiled sound.
I think it it's rather transparent and relies more on the source than anything else. With that said I can see how some would call it an "polite" amp in the respect that it has a slightly more mellow sound than the iDSD BL for example. I never really "got" the whole TubeState thing by the way; what it means and what it does to the sound to be honest, the amp sounds really great regardless.
The Black Label on the other hand is more lively, a dac/amp with punch and extension and I choose it over the Mojo simply because it had a much more dynamic sound (in my very humble opinion). It is a terrific device that'll do even the hardest to drive justice.
I deeply recommend you to listen to them if you get the chance, especially the iDSD BL.
I don't have DF Red, but DF v1.2 was a huge sonic disappointment to me.
I never got the chance to listen to v1.2 or the v1.5 (Black) so I can't comment on them but the Red is good but not without flaws. It has been relegated to non-serious listening since the iDSD does everything sooo much better in my book.
It generally seems to be considered "leaning on the bright side" and at times it can come of a bit analytical and lean&clean. From what I read, most people prefers the Red to all other Dragonflys and I can understand why with the equal amounts of punch and clarity it packs in such a small package. The amp-section (it most certainly is a dac + amp) does a good job dealing with the sabre-glare though and paired with warmer headphones I think it can sound really good.
On the other hand, I have heard "lesser" devices (with XMOS implementations of which the Red lacks) do most of what the Red does good so all things considered, even if I think it's a great device, it is a wee bit expensive.
I did buy Sabaj DA3 though
That thing looks really exciting, ticking of all the right boxes honestly. I might be tempted to try one, especially considering the dual dac/balanced output.. Have you received it yet?
I'm currently waiting on the shipping of my Fiio X7 mark 2, should be arriving before the weekend and I hope it will be a great match with the Takstars.
But that's good for you, one less competing with you for it haha 
