Does the dealer hit or stand on a soft 17? Can you double down after splitting? Can you surrender (early or late)? In general you're probably looking at about a -.6% disadvantage, but the penetration seems reasonable. That's not an easy game to beat.
It changes some of the decisions because you don’t know of the dealer has a blackjack until after everyone has played their hands. You would be more hesitant to split or double against the dealer’s ten and ace in that case.
It's beatable, but it's far from a good game. The deep penetration i've seen in the UK is a plus and there are several other opportunities, but the truth is that just straight counting won't make a huge amount unless you are very aggressive with your spread.