Nice headset.
I bought them primarily for work. I'm on a lot of calls (on my PC), maybe around 3-4 hours a day a couple times a week and I find them to be pretty comfortable. I'm not sure how they would be if you used them 8 hours a day, but I can't imagine it would be too bad.
I also use them occasionally for listening to music and Youtube. Personally I think the audio is pretty good, but if you're an audiophile you may have a different opinion. But for a casual user like me, they're perfect. They work equally well on my phone.
The build material is pretty good if you ask me, but I do think you need to treat them with care, they aren't that durable where you can toss them around willy-nilly.
At the price point I paid (around $40) I think it was a great deal. I don't think they're worth the $80 or more I normally see them priced at.
Its not made with the highest quality. But for the price, it does the trick and the sound and clarity is surprisingly good. It's light weight which I guess might account for it feeling cheaper, but on the other hand, the light weight when its on your head for a long time is pretty nice.