Boulders is heavily involved in a lot of community events and for that, they have my appreciation. Their beer selection is excellent, and their food is reasonably good. However they perpetually under-staff table servers, making for very slow service. It is not uncommon to wait for 20 minutes for a simple drink order. I can't speak to bar service, but eating at a table Boulders is an all-evening affair.
It doesn't do a lot of loud music, but it gets crowded at times and the noise level makes it a bit excessive. Sitting in the upper level is usually quieter.
That said, it is not a bad place. You could certainly do a good deal worse for bars in Tempe. They have a good community of cyclists and climbers, and you can often meet interesting people.