You are correct - the playoff games are going to take longer (it was 1:45 for 3 innings last night) b/c there is no tomorrow and you have to pull pitchers a lot faster. You don't need to eat innings if there is no tomorrow. The national TV games also have an extra 20 secs each half inning in commercials. IMO the batters and pitchers (see Jeremy Hellickson and Odubel Herrera) have gotten into the habit of making the time between pitches too long. I know the minor league games are a lot crisper when you see it played. Next year I read 70% of the major leaguers will have played with a pitch clock in the minors.
Matt Breen wrote an article in the Inquirer about this last week -- this year there are 47 batters who take more than 25 seconds between pitches (Herrera is #1 at 29 secs), 10 years ago the number was 7. Four secs faster per pitch for a 250 pitch game is a lot of time. I know Manfred can impose the clock next year (already negotiated) but he is trying to get the players to agree to a change. Change is coming.