It depends what you listen to.
I would contend that the Sennheiser 6__ series can do some things the “best” of any of these. It might be the worst at other things, but that’s headphones, right?
The 58x are perhaps the most well-rounded and least extreme of those qualities however. I think everyone this deep into the hobby should try this line of cans, and this is by far the price to dip into them at.
See that makes sense to me, but I’ve also read a lot that Sundaras are better, and a logical upgrade to the 58x, so if they’re not gonna make me go “oh wow, these are as good or even better than the Sundara- which makes sense because they’re based on headphone more expensive than the Sundara, or are gonna provide a radically different experience than those” than I’d rather save my money and put it towards an Ares II or something. If I had a tube amp, sure, but I’ve got a G111
This thing is back at ~90$USD (or 134$CAD on Amazon.ca) if you want a little amp for your speakers, but want to try something other than the SMSL SA100 or the Topping PA3.
SA100 got volume control and Bluetooth. Topping PA3 got volume control. This one is simpler: Power on the front, the only volume control is with a screwdriver on the back of the unit. You can fit two horizontally in a rack. Bridgeable. If you already have a volume and want monoblocks, this is a cheap way to try that.