Such a move can improve your results for several reasons. If you’re a struggling cash game player at your current level, you may want to step down a level or two. In simple terms, if you take the stress of your game away from winning and emphasize the learning process, eventually you’ll improve your game and get back on the winning track. Mixed games, of course, require all of these lessons, which is why many pros favor such a blend of games in both the famous “big game” at Bellagio as well as the $50,000 buy-in WSOP HORSE tourney. Seven card stud reinforces the ideas of counting outs and not chasing longshot draws. Pot-limit Omaha can help you learn about controlling the size of the pot as well as how to read various possibilities on the board, especially in the high/low variation of the game. For instance, Razz (seven card stud low) can teach you the true value of starting hand selection.
If you want to step away from hold’em temporarily, other poker games can teach you needed skills that you can still apply in your hold’em arsenal.
If your primary specialty is no-limit hold’em tournaments, you could try a low-limit cash game to learn patience, pot odds and turn/river play.