The scaling option says "target unconscious for duration", so that means he is unconscious for 1 round, unless you have increased the duration with the "Increase Stun" scaling option.
As for your question about casting sleep versus jolts - that is up to the player to decide. Jolts is meant more as a stunning spell, not as a sleep spell. The unconsciousness portion is just an extension of the stunning result, and most likely only going to be used by more powerful mages.