I think the only two that could really use it are Magnezone and Lanturn. Freeing up the Thunder Wave slot for one more attack is supremely useful.
Ex: Lanturn could now use:
Surf/Ice Beam/Discharge/Rest. It can still para efficiently, but it has room for Surf, which has the exact same power as Thunderbolt anyway and gives a much more powerful attack to levy against the likes of Rhyperior, who could scarf down your mediocre SA unSTABbed Ice Beams like nothing.
Magnezone sets that don't use Thunder Wave to begin with should just keep Tbolt, but others should replace Thunder Wave for something like Magnet Rise, Tri-Attack, or Flash Cannon.
On Ampharos I'm mixed because it has the massive SA that allows it to OHKO with Tbolt and fairly solid defenses, but unlike Magnezone it has no good resistances so the only thing "tanky" about it is that it probably won't die in one hit to anything other than STAB Earthquake. That is what made the defense-oriented Ampharos with Counter an annoyance, because it would generally survive with enough HP to Tbolt or HP something else to hell before you could finish it.
