Purchasing the HD800S gave me the piece of mind you’re (implicitly) looking for. I recall being anxious about trying new stuff. But that probably happened only because the HD800S ticked two open checkboxes I had back then:
– What is like to hear a (namely) high-end headphone?
– What the hell is this soundstage anyone talks about?
I lived similar situation in my other (guitar) hobby. I remember wanting a Fender (and a Gibson Les Paul) so deadly. Got the Fender almost 4 years ago and never looked back getting the Gibson. Weird, huh?
So maybe you need a checklist of characteristics you’re looking for and then narrow down the headphones that are able to present these features? This is how I would start. Good luck. 
Game has changed now they’re producing something similar to Sennheiser offering (but with supposedly better foam). Bought two sets and installed them in the 600 and 660S. Did not notice the wonkiness given by the other thick pads they offer. Link below:
Cheers. 