I didn't catch any sea trout, but I did alright on the pike, and I made a small film of one of the pikes I caught.
Brackish water pike are quite different from their freshwater cousins. They are definitely stronger (just watch the bend in the rod in the film - they pike weight 5 pounds, I think), and they're very beautiful with distinct markings. Even the takes are fiercer - these fish mean to kill when they strike.
Most importantly from a fishing point of view, you can have action all through the day. It'll slow down and pick up, but unlike freshwater pike, you can always illicit some takes, pulls and catch the odd fish. In freshwater, pike have distinct periods of inactivity, where the lakes just seem dead. and all of a sudden. everything turns on with a few minutes.
In freshwater, I often use really big flies - as big as I can cast them, and the really big ones are less effective in brackish water, where imitations of the pike's prey seem more important, and sometimes I used flies that could easily have categorised as a big sea trout fly.
When landing pike, keep an eye out. They have hundreds of razoe sharp teeht that can cut you quite badly. The gill grip is easy to perform, and (relatively) safe, but keep an eye out and stay alert. If the pike, when in the surface or being landed, open its mouth, a heavy head shake usually follows, and then it's either a question of holding on if you have set the grip, or letting go to avoid cuts. Once you have them in the grip, they usually stay calm.
Have a great weekend - go catch a pike :-).