The chief advantage of sevoflurane over the other commonly-used inhaled agents used in anesthesia is that sevoflurane does not make the patient cough. The other agents are irritating, and are generally used after the patient has already been put to sleep and intubated because severe irritation could cause laryngospasm which makes it hard to breathe.
Sevoflurane can be tolerated while awake. It smells mildly bad, but for children there is often an added smell to mask it, like cherry or bubble gum.