(sidenote: The Apple Store is on Regent Street...Oxford Street runs near it)
The Regent Street store handles launched very badly as the queue blocks other shops and causes chaos. Given the amount of room at Covent Garden you'd be crazy not to go there insteadIt's only about 5 mins walk away.
Only if you are an Olympic athlete!
Sorry to be pernickety, but someone might take you literally and every minute could count on a release day!