I've read that the flavour is "lighter", which might be a plus.
Brook trout are actually members of the char family. They are lighter than some salmon. But if they are wild caught, they've been eating fresh water shrimp, and scuds. These are high in beta carotene which stains the flesh a beautiful orange color, and imparts a wonderful flavor, as do all the underwater nymphs and crayfish they feed on. Hatchery raised, and farm raised brookies have white flesh, and are nearly flavorless. I would assume that arctic char are the same. I know that wild rainbows and steelhead also taste much better, and are healthier than farm, or hatchery raised. The stresses that they encounter in the wild, plus the better water quality, and food quality makes a huge difference.
If you are interested, see what Montana did with their wild trout populations, and how they found out that hatchery raised fish actually damage the troujt populations of streams, lakes, and rivers. When left to propagate naturally, in good water, the salmonid species thrives. It is when we step in and try to
fix things that fisheries become dicey. Colotado is learning the same thing.
The other problem with farmed dish is that if there is a break in the holding nets, fish escape and carry disease to the wild fish populations, and often breed with their wild counterparts, degrading the gene pool, and damaging the indigenous, wild fish strains.
We are continually finding that as we try to change the word to match what we think is how we want it, we are actually hurting ourselves, in the long run.
If you're not a salmon, or trout fan, then choose a sustainable, wild caught species such as Pollok, or other sustainable fish. The following link gives a pretty good list of fish to choose, and fish to avoid.
https://en.wikipedia.org/wiki/Sustainable_seafood
Srrrrya; Chief Longwind of the North