>You'd also have to take into account that the sites are monitoring things like reaction times to bets and raises, hand range consistency, etc.

You might be surprised by the lengths people go to in order to bypass bot-detection just for ordinary games. All of the things you mentioned are pretty standard. Considering there is serious money on the line here, I am positive that plenty of poker bots will be virtually indistinguishable from professional players, if they aren't already.