The terminals in the US can support Chip and Pin.. its the cards issued that lack the encryption (ie: no pin to decrypt the contents).. so its essentially replacing a easily copied mag stripe with a more difficult still relatively easy chip tech.. the entire point of the PIN is to encrypt the card contents. It would have made more sense to get everyone on Chip and Pin (hey, you are transitioning anyway.. just bite the bullet and go all the way... but somehow the US still ended up with a crappy system.
Most of the speed issues in the US stem from the card terminals support chip, but they take longer because they first attempt a "decrypt", which fails, then it falls back to clear code.. then you add this that its being processed at the Register, not the Card Reader. the Card reader is quick, but they moved the "processing" into the POS which is slower because its converting it back into the data stream that the old mag stripe had.
In short.. crap or get off the pot.. commit to Chip and Pin or don't.. the half-assed solution is what is pissing off people.