Blackjack question - Do you take much heat when hitting soft 18 (Ace/7) against dealer 9, 10, or ace?

If the dealer has a ten or an ace showing, I would always hit on anything less than 17. If they have anything less than a ten or an ace then stick in hopes that the dealer busts. Hitting on 18 either way is absurd, if not a little y. Kudos to you if it's paying off though.