I'll admit I was hesitant to buy one of these chairs, having seen advertisements of it being an ideal office chair for guitarists, but finding hardly any reviews on them, and a couple mixed reviews on the desks.
After not being convinced by my other options, I finally pulled the trigger on one of these, and I'm very happy with it. Everything feels sturdy, in line with decent quality office chairs you might find around. The Foam seat is the right amount of firm, and looks to have enough that I'm not worried about it bottoming out. Though I imagine the Viking would be much better, this chair has a decent amount of adjustability - height, back incline, headrest has two points of rotation, armrest height and sliding both forward/backward and/in-out. And of course the advertised armrest rotating out of the way. Even though there's plenty of office chair plastic, everything, including all of the adjustments, feel sturdy. The chair glides great on my floor, and is pretty silent.
The one downside I can think of is that if you're a larger person, this chair might be too small for you. I am 5'7" 130lbs, and this chair feels just about the perfect size for me, and although the headrest has a large amount of scalability, I could see it feeling awkward on a larger person. Likewise, I have plenty of room to move my legs/sit cross-legged, but for someone larger, I could see them feeling more cramped. The seat base although comfy does look smaller area-wise than the Ikea Markus I had before this. That said, the Viking's measurements seemed a couple inches larger than the Voyager, so the Viking may work for you if you're a larger person. Also, as one of the few reviews I could find on this chair said before, probably get the foam base version if you're going to wear shorts or put your feet up. The Mesh is more of a hard plastic mesh. It's similar to what I've had on other office chairs and plenty comfortable on your back or in pants, but putting your full weight on it with only bare skin would probably be uncomfortable.
I'm very happy with this chair, and glad I got it! I look forward to making music in this seat!