Another dilema I don't need

Used but like new Hifiman HE6SE V2 Audiorama Edition for $599 or brand new Modhouse T60 Argons with Viking Weave cable & Xenon Suede pads for $594?

I’ve got a Topping A70 Pro on the way. That’s what these will be used on.

Those are pretty different headphones. Would you prefer closed or open back? The HE6SE is one of my favorite headphones with it’s superb detail and dynamics. But I only use it with EQ since I’m not a fan of the stock tuning.
I suspect the Argons would have better stock tuning—though I’ve never heard them.

My purpose of choosing the HE6SE or T60RP Argon is that they are planar magnetics that both need a lot of power to perform their best, which the A70 Pro provides at 17wpc. I haven’t heard either of them as yet. I only know both the HE6SE & the T60 Argon have a cult like following.

I have a pair of Beyer DT1990 Pro that I use with a Singxer SA-1. That SA-1 is also my preamp that I use with a Hafler 9505 powering a pair of Tannoy XT8F towers. Those Tannoy are what I listen to most frequently.

I’ve got an Xduo TA26 & I think I want to pair it with Grado’s, probably the Hemps. I don’t yet have the Grado Hemps.

I like the idea of things to be matched up to what they’re best suited, although I realize the Hafler 9505 would be fantastic on most any speaker. The Singxer SA-1 & Topping A70 Pro would be great on most headphones too.

On another note, I’ve also a pair of Beyer 600ohm DT990 & I thought those would be great with the TA26 but no. That combination begins to distort too much when turned up to reference levels.

I want a nice planar in any case. No way am I ever going to buy Susvara or even Tungsten headphones. These I could afford though, the T60 Argons or used HE6SE.

If want a nice planar I suspect you’d be happier with a Arya SE which has better tuning. And can be had for a great discount nowadays. The HE6 is the highest tier headphone of the bunch. But doesn’t have the best Synergy with Topping amps despite their power.
If you’re not picky about tuning and want the best technical performance, then go for the HE6

I forgot to mention that I do have a Yamaha P2200 clone, an Avantone CLA200 that is a spare amp I have. It’s 200wpc @8 ohms, class AB. Its a big heavy SOB. I saw Z Reviews using his old Phase Linear amp on some Susvara’s I think it was. Anyhoo…