A Metal musician, should be versed in a variety of guitar neck types, for the experience alone!!!!! My ESP LTD M100, could not have a smaller neck width, and thickness ratio if it tried, likewise My Schecter HellRaiser C-7 FR, has a thicker, and wider neck, like My old Les Paul Custom I used to own, and the Ibanez RG2228-GK, has a wide, but very thin neck.
 And the ability to apapt to multiple neck types, and how one has to adapt their playing to the neck, is great experience, if You are ever caught in a gig situation, in which you can not play your standard guitar, or already use different guitar types.
 The different neck types, will also affect the way you write, when you can fool around on such different neck types: As musicians will note, that they can see how the thicker neck can help with certain things, such as sweeping arpeggio's for some musicians, etc.., ---and depending on the size of your hands, length and thickness of fingers, etc.., will dictate the types of guitars you prefer, yet a variety, within your already acceptable range, will do you good.