I lived in Spain for a year, and everyone had chips there. My US card always drew eyerolls as they had to find the /old/ machine and dust it off and find someone who remembered how to use it. I was excited that we were getting chips here in the US, but of course they fucked it up and for whatever reason it takes ages for your chip to be read, and there are frequent chip read errors.
In the US, it depends entirely on the point-of-sale system. Some are just as fast; some are a lot slower. My guess is that the slow ones are using the same old CPUs that the previous "stripe-only" ones did, which just aren't powerful enough to handle the added cryptography requirements in a reasonable amount of time.
Chip cards work super-slow in the US. I often pay in cash because it's so much faster. I take the same chip card to the Netherlands and it works in a few seconds.