I just took the LCD-4s for a spin all afternoon in a private listening room at a local hifi shop I frequent. I really didn't feel them and was quite disappointed given the hype and that I'm a previous LCD owner. They had a constrained soundstage, lacked bass texture and detail, and in the end only seemed to have decent vocals. Even that wasn't impressive, it just seemed to be the best thing they could do. I tried them with 2 different amps and DACs, then A/B/C'd them with HiFiMAN HEXv1s and HEKv1s. Once getting the HEKv1s on I felt I'd thankfully returned to "high end". The LCD-4s really underwhelmed me and I comfortably place the SEM1s above them in all categories except maybe vocals?
This isn't a direct quip at you, to each their own, but I just found it a funny reference to "if you want to hear real quality, check out XYZ headphone". As far as detailed, fast, and textured bass goes, I'm still a major fan of the original HiFiMAN HE-6 4-screw. The Pioneers are nice to me overall, but they don't have HE-6 level bass, but nor do the HE-6s have Pioneer lever soundstage or organic instrument imaging~
I was also unclear from your posts as to whether you tried the SEM1s in a real listening environment or tested them out against any other headphones in a shootout that wasn't at a show? I'm not a naysayer of graphs, but most the people I find shooting down the SEM1s reference the Innerfidelity graphs (which I'm not disputing the accuracy of) and haven't gotten legitimate head-time outside of a show floor.
Hey I'm glad you found something you like! I certainly would disagree with your assessments, but this is a subjective hobby (regardless of the objective measurements ). I have tried the Pioneers on two separate occasions and they sounded to me like they measured (so not very good), but hey, you like them and it's your $$$ and in the end your opinion is what matters.
I just want to clarify that the LCD-4s are VERY hard to drive properly and an amp that can output minimum 2 W is needed. I found that the Chord DAVE as a standalone wasn't ideal for them next to amps like the Cavalli Liquid Gold or HeadAmp GS-X Mk2 (both can output north of 5W).
YMMV of course.