Hi. Just wondering what your opinion is on replacing the adjustable graphite nut with a adjustable brass nut that the older Warwicks came stock with. Warwick swears the newer graphite nut outperforms the older brass nut. My concern is that one of the tabs broke off of the graphite nut on my SS II, so I replaced it with another graphite nut. While inspecting the replaced graphite nut however, I found it to be somewhat concave, maybe from use or pressure. I've heard this complaint before and am wondering if it is a worthwhile upgrade/downgrade/change to install Warwick's adjustable brass nut? Does this need to be done by a luthier? The brass nut can be obtained from Warwick for $30.