This is my biggest sticking point. I don't want NFL-esque instant replay reviews taking 5-10 minutes each. I don't want umpires down in the replay booth looking at frame by frame pictures of a play at first and all arguing if someone was safe or out when really the best way to tell was watching the play live and listening for the slap of the ball in the glove and watching for the runner's foot on first.. There are limitations to instant replay. Even tennis, which has the best replay in sports, takes 5 seconds to review an in/out call, so it may not really be possible to instantaneously call balls/strikes, fair/foul, etc. There is really just a spectrum of how invasive instant replay will be in the flow of gameplay, and I think many of us have different opinions on where along that spectrum we would be happy. If they could immediately make every call with computer-like precision, would I be for that? Yeah, sure I would (though again, I do still enjoy players adjusting to an umpire's strike zone. That's just a difference in opinion though). I just worry that expanding instant replay from homeruns will soon lead, in time, to replaying everything including trapped balls, bang-bang plays at first, etc until it's like football where, really, instant replay just doesn't work a significant amount of the time (would replay have helped in the 2005 ALCS with AJ Pierzynski's dropped strike 3?). Also, just a thinking point, it's easy to see a blown call once, like the other night, and say replay is great. But since it was implemented, the 2 overturned homeruns the other night doubled the total of changed calls since replay started last August. 4 calls (vs. 10 reviewed and upheld) in how many games? I'm not saying the current system is bad (though I'm not a huge fan), I'm just saying I don't think you can point to one changed call (or 4 total calls in 3 months/~1300 games) and say it's very necessary in the grand scheme of things.