Although this card rarely is needed since Pokemon can retreat, I always make room in my deck for at least 1 of these cards.
Retreating is a major thing in the game, for both modified and unlimited. A lot of the time though, retreat costs are too high to be payed off (especially in the case of special energy, with GoW in unlimited or a heavy attacker for modified).
There are a lot of other good choices like this, such as Warp energy, fluffy berry and most importantly Warp Point. However, Switch is a card that can fit neatly into almost any deck, whereas some others can't.
What puts Switch above Fluffy Berry is that its not a tool (there goes a Gold Berry) and it does not count as a retreat and removes status conditions. Since there is once per turn retreat limit, a Computer Search can be used to get a Switch to replace an active or heal a status condition.
Warp Energy is an energy card, and attaching it to a Pokemon that's going straight to a bench isn't usually that useful.
Warp Point is a better card IMO. But sometimes Switch has the advantage.
I always play this card. It's simple, common and can make a game breaking difference.
Modified: 7/10 (overall heavier attackers in modified)
Unlimited: 5/10
