There are places in the city that are worse than others for performance but I’ve only ever noticed stutters and the like while driving. Do you use power utils? I don’t have an overclock but I make sure the governor is set to performance. Could just be luck on my end though.
From what I’ve read, it seems to be a compromise to me. I imagine the dev team didn’t want to do it but compromised with the publisher and in reality they probably don’t want you to buy the dlc, as it defeats some of the design decisions. There’s a good pcmag article detailing the dlc and how impactful it is. My guess is that the general opinion of any reviewers would remain the same regardless (with the context of the pcmag article).