Yes we talk about the same Headset. I have the black one. Thats interessting, cause i also wear glasses and had no problems with that one. The only negative thing for me was the summer. My ears wear sweating a little bit to much for my taste in this headset. But as i said no problems wearing it.
We played i think more than 14 hours a day on this bountie weekend and i didn't have aching ears or a aching head. And i would consider my head as "realy big" too.
I can't wear baseballcaps for example. None of them fits on my head.
I absolutely love my Sennheiser in-ears for listening to music while traveling, so when my old headphones (Creative Fatal1ty) broke after 5 years of intensive usage, I went for a Sennheiser headset. Ended up getting the PC320 specifically because it's supposed to have even *less* pressure on your head/ears than the Siberia according to all tests. Still, the first few weeks it really hurt. I found a workaround which was to artificially "stretch" it by putting the headset on a box whenever I didn't wear it... and now it's kind of okay, but still not perfect.
Looking back, I should've re-bought the Fatal1ty again (and I'm considering buying 2-3 of them just to have them in stock, especially since they're so cheap). It's like shoes - if you ever find a perfect pair, buy 3 of them (if they're affordable ;)). But to find the perfect one is really difficult. I'd suggest you go to a big electronics store and try a lot of them to feel what "fits your head". In terms of quality they're all pretty similar (unless you're an audiophile, in which case you wouldn't ask nor read this thread) and there's lots of bias and brand-worshipping (look at how many people are wearing Beats, which are probably among the worst headsets ever). If you have reference points, however, from trying some of them in a store, you will have an easier time reading all the reviews. For example, I've never tried the Siberia headset, but since reviewers say it's even tighter than the PC320 headset I know for sure that I wouldn't like it.
TL;DR: There's no one-size-fits-all solution, but everyone has their own preferences. Go to a store, try some out, read reviews, relate them to your experience, and make your choice.