Reel seats while both functional as well as aesthetic are the eye candy of the fly rod world. Nickel silver, aluminum, metal insets, exotic wood inserts oh my!
Reel seats come in many flavors from up-locking to down-locking to cap and ring style.
As A general guide Cap and ring style work well from 3 -5 wt rods. 6 wt and above are served well with up or down locking reel seats.
Nickel silver is more traditional while aluminum saves weight.