Just making a note that, on non-mega Scizor, Acrobatics is better just in case you eat a knock off, while 5 BP isn't a notable drop in power anyway.
So that this isn't a shitty 1-liner, I'm just going to bring up something that people often use even though they shouldn't. BTW, I'm not saying that either of these are common, but I'm just saying that for whatever reason you see people using this even though it is bad. Sorry if this has already been done, but its not in the archive so...
Don't use this:
Galvantula @ Focus Sash
Ability: Compoundeyes
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Sticky Web
- Thunder
- Bug Buzz
- Energy Ball
or this:
Smeargle @ Focus Sash
Ability: Own Tempo
EVs: 96 HP / 120 Def / 40 SpD / 252 Spe
Timid Nature
- Sticky Web
- Stealth Rock
- Spore / Dark Void
- Magic Coat
Why they're bad: Sticky Web isn't very good in the first place, but using an inferior setter just turns "not great" into "bad". While I get that they are the two fastest setters yada yada yada it doesn't mean sh*t if I am losing my only setter of the thing that means my team isn't at a disadvantage on turn 2. Seriously: hazards are easier than ever to get rid of, so being able to re-lay Sticky Web is a necessity on a webs team. Therefore, Galvantula and Smeargle simply doesn't fit the bill due their extreme frailty.
Instead, use this:
Shuckle @ Mental Herb / Custap Berry
Ability: Sturdy
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
- Sticky Web
- Stealth Rock
- Encore
- Infestation / Toxic / Knock Off
Why it's better: Shuckle's bulk allows it to lay hazards multiple times per match as opposed to as a suicide lead. It is very capable of being problematic for your opponent too, with access to Encore to prevent it from being set up on, dual hazards, Toxic and Infestation for passive damage and Knock Off for utility. It is just better at what it does than all other setters are, and as such it is the only one that should ever be used in OU.