That's a really interesting comparison. I think brunost has a lot of flavours that are nothing like Marmite - it's creamy, it's sweet, and it's a bit sour. But they are certainly similar in that they have a sort of concentratedness to them, and in that sensible people hate them.
I also made it once. The electricity for boiling all that liquid should be what makes up most of the manufacuring cost. Hm I should ask Fjällbrynt how they cope with that.
If I remember correctly the trick was in the stirring. Either not stir at all (with the risk of burning), or stir all the time to keep it from crystalizing.
That is why my comment was full of caveats! I also felt like maybe the taste was not really comparable. But I think you nailed it with the last sentence!
