Yes it is.
Though choice band is also a viable option, choice scarf is for those who want to quickly take out the target. Here is a choice scarf moveset:
Item: Choice Scarf Ability: Sturdy Nature: Jolly / Adamant
Moveset: EVs: 252 Atk / 4 Def / 252 Spe
~ Close Combat
~ Ice Punch
~ Stone Edge
~ Toxic / Earthquake
Choice Scarf Sawk sacrifices a large amount of power in order to become one of the best revenge killers in the tier. With a Choice Scarf, Jolly Sawk reaches 442 Speed, enough to outrun every unboosted Pokemon in the tier and many boosted ones as well. Even without a Choice Band, Close Combat still does a lot of damage to most offensive Pokemon. For instance, it is able to OHKO Dragonair lacking Eviolite and Raichu. Ice Punch offers good neutral coverage alongside Close Combat, hitting Grass-types such as Vileplume moderately hard. It is also Sawk's best option against Golurk. Stone Edge hits Flying-types such Rotom-S, and gives Sawk a way to hit Ghost-types such as Haunter and Misdreavus. The last move should generally be Toxic, as it gives Sawk a way to cripple the many Pokemon that completely wall it without a Choice Band such as Tangela, Alomomola, and Shelgon, greatly limiting their staying power. However, Earthquake is also an option because it gives Sawk a move to hit grounded Poison-types such as Garbodor and Arbok who would otherwise set up on this set with ease.
: http://<img src="http://media.pldh.net/pokemon/gen5/blackwhite_animated_front/539.gif" alt="sawk" />