X3 on Grados being exaggerated in the lack of comfort arena. Comparing them to my Senn HD 201's and my Denon AHD1001's, they actually more comfortable than the HD 201's. They're not AS comfortable as the Denons, but I've yet to find any headphone that is.
I have a fairly large head and I've never had to stretch the headband at all.
If you buy the upper level Grados and the bowl bothers you, buy some of the Grado flats (you can usually find them pretty cheap on somebody who bought SR60s and wanted to replace them with bowls) of the much mentioned Sennheiser 414 pads (these can be hard to find not on backorder, because they're so popular).
The Grados have really quick drivers, which are a godsend for metal, which is a really quick and dynamic type of music. Notes don't linger on the Grados at all. With some other headphones, I can find listening to metal a bit confusing, as when a lot is going on really fast, everything kind of gets muddled together. Not the case with the Grados. Everything is precise and crystal clear.