Fly rod reel seats offer a number of different pros and cons based on its design and intended use. Not only does a fly reel seat balance the overall rod out but also can greatly affect overall weight and usage.
Building a small stream light weight fly rod then a lighter weight cork style reel seat is a great match. Heavier fly rods where there is more pressure and strain on the fly reel require a more robust and durable reel seat, double unlocking reel seats are secure option and greatly reduce the change of the reel becoming loose over the course of a days fishing,
Things to consider
The double up-locking reel seats are a great option for 5wt-9wt fly rods and are salt water safe in the carbon trim. Extra care should be taken if using the wooden double up-locking matt gun metal reel seat in salt water conditions.
The down locking reel seats are a great option for Euro Nymph rods as well as lighter weight 0-5wt fly rods.
An up locking reel seat featuring the RFF take on 3K carbon with blue pearl effect.