Originally Posted by Fat cim
You can't break any walls with Slaking, because walls get free recovery every other turn, and you can't beat a sweeper team with Slaking, because a smart player will just switch in an immunity or sacrifice something and then bring in their set up sweeper. So what is it useful against?
This is pretty much Slaking's whole problem, you cannot really apply constant pressure with it, meaning that anything less than a OHKO is actually making you lose some serious tempo.
While dividing Slaking's stats by half is retarded, he's making you take double damage everytime he fails to ko a pokemon. Because of this, he ends up being pretty similar to Ambipom, you want to hit hard and fast but you cannot really stay in properly, you have to be predicting correctly to actually deal some damage. Slaking has the advantage that it can switch in on more stuff, but it's poor defensive typing makes it bad at it. Relailate is an awesome move on Slaking, but it's about as predictable as Ambipom's Fake Out and even more narrow.
So yeah, Slaking is pretty similar to the two-tailed monkey, which is to say, not very hot on Underused. Slaking hits considerably harder but Ambipom has a much better speed.