Basically, chess960 skips the opening phase. You go straight to the middle game: and often into positions you haven't seen before. It's perfect for tactics training indeed.
However, a downside is, that in a classic chess game, since you often play the same openings, you often get into familiar positions. You remember what you did last time, know the strengths and weaknesses of each side. Chess960 doesn't give you this expirience because the positions are different each time.
But being out of familiar territory really does train your tactics, 'cause you can't rely on common patterns. The games are very rich tactically.
I have never played a game of chess 960, but I was wondering if this variant can really teach us anything about strategy and tactics to be useful in normal chess games, or is just a distraction for serious chess players?