Finally got myself a copy of both expansions!

The first thing I looked at was how to combine them into one campaign. It is said, that you can either start Chains with set XP/gold or just continue with what you've got from Mists. Everyone will get 5 XP ff you just start "fresh" Chains, but you if you start with Mists in mind, you'll get all XP from Mists + 1 extra for the final, so that's 6.

Did I miss something?

Remember that if you play chains alone, you start with the first quest (castle dalibor) then move on to the mid section of the tree. If you conrinuee a mists campaign, the mists finale REPLACES castle dalibor.

Mists on its own has

Intro

3 quests (act 1)

Finale

Chains on its own has

Intro

3 quests (act 2)

Finale

When you combine them, the mists finale acts like the interlude, and you skip the Chains intro:

Intro (Mists)

3 quests (act 1, mists)

Interlude (Mists finale)

3 quests (Act 2, chains)

Finale (Chains)

I guess a shorter way to answer the question would be, "regardless of whether you play split or together, just before the finale of chains (and for most of Act 2) you'll have the same amount of XP."

. If you conrinuee a mists campaign, the mists finale REPLACES castle dalibor.

Oh, I missed this bit. Thanks a lot, that explains everything! Too bad, that this quest probably would never be played though.