Summary: pretty decent, quality ingredients, but nothing mind-blowing.
Finally got a chance to check out Glory Hole after putting it off for awhile.
Popped in at about 11am on a weekday, there was no line and all of the donuts were fully stocked. After mulling over the myriad of choices, I went with a Beer donut at the girl behind the counter's recommendation (who was really nice and helpful).
I enjoyed the donut: it was surprisingly light and airy, not super flavourful, but not overly sweet either. The portion size is pretty huge...about twice the size of a typical coffee shop donut. Because of this, and the obvious quality of the ingredients, I feel the $3.50 can be justified (especially as a 'once in a while' treat').
What I really liked was because the donut is so light, I didn't feel weighed-down/gross after eating it (like you can from a most donuts).
Overall, I enjoyed my experience and will definitely be back to try out some other flavours. Maybe alter my review after I see what else GH has to offer.