Yes, I have had several sony headphones wih PMX 80’s style and they don’t fit very well.
Is the PMX70 the same as PMX80? I could not find PMX70 on Sennheiser website.
Have you found the rear part of the PMX70 uncomfortable when doing bench presses? Or maybe is not possbile?
I guess if there’s only minor discomfort when lying down then I would go for the PMX70.
The PMX80 is the successor to the PMX70. Do a search on Amazon’s site and there’s a customer that compared the two as he owns both. He basically said the 80 has a slightly improved bass and trebble response but it’s not that dramatic. The basic mechanical design is the same.
I don’t do workouts inside, just running (hate exercising indoors). The headband sticks out about 1" from the back of the head so it would not be good for bench presses. My wife works out a local YMCA and didn’t like my PXM70s for that reason. I do not have big ears and am not a big man (only 5’ 5"). I do not find the comfort of my PMX70s a problem at all; they are not too big at all and with the silicone sleeve on it they are comfortable for me. My ear canal openings did ache a bit when I first got them after a few days of usage but that passed. I wear them an hour at a time and they don’t bother me at all, and I’m finiky about fit and sound quality (hence why I say they’re okay, not great sounding). The only downside I see is sweat can roll down my temples into the ears but that mainly happens on really hot days (temps above 95F).
I would recommend the OMX line instead, or those ones that twist/fit in your case. The PMX line is really aimed at runners as they are pounding/bouncing a lot and that’s one of the easiest ways to have the earphones slip out. In a gym, the OMX line would be better or those twist/fit ones Sennheiser makes. I still think they make better sounding transducers than Sony (personal opinion).