I've used alakazam on a few of my HO teams of middling success, and the LO Sub set is pretty much guaranteed to net a few kills or a sweep against any HO player who's stupid enough to let him get a sub up.
However, I think the most difficult thing is actually getting that sub and keeping it against players who know what they're doing. 95% of the time when you're facing a zam, it's the right play to just stay in and attack just in case the zam subs, because if it doesn't have a sub or a sash it's pretty much a sitting duck for any of the fast, powerful scarfers in today's meta. It's just not worth the risk of switching out just in case it subs.
Both sash and LO+sub have their merits, but I generally found sash to be useful in a much greater variety of battle scenarios. The sash set works as a great "last resort" revenge killer while still being able to clean up late-game pretty well
I've got my ACME rewards card.