I think full loadouts are far more important than an individual perk. While Sleight Of Hand can give you a speed advantage, I rarely use it with my sniper classes. Good video overall, but such a heavy focus on that one perk makes it seem like you need it to do well.
For my sniper classes, I find this combo to be particularly deadly (note: I'm a true sniper AKA "hardscoper", and I think quickscoping is retarded):
[sniper rifle of choice]
+ Attachments
+ Silencer
+ Thermal
+ Blind Eye Pro
+ Assassin Pro
+ Marksman Pro
+ Smoke Grenade
+ Bouncing Betty
[strike package of choice]
[death streak of choice]
With the above, you can really hide well and get dug in somewhere. If you stay in scope like I do (vs. only scoping to shoot) and are smart about choosing your spot, you can rack up lots and lots of kills before the enemies will catch on to where you're hiding. It works wonders on Terminal, Bakaara & Mission, especially.
