Yeah, they still brake way early on lap 1, after that I can go side by side with them and they don't back down, which they definitely used to have trouble with (put your nose inside at corner entry and they'd just give up). So far I've only driven on the Career mode series though, not sure they work in all cars.
Something I'd like to see is a bit more variety in the source of their slowness though - right now they're good from corner exit to corner entry at any AI percent, but slow in the corner. Would be nice to have some AI who brake earlier, or get on the throttle later, as it is the only passes on straights are due to drafting & setup.