Well, when there was talk about steps back in previous versions, I definitely did not have the issues that other people had. That doesn't mean it is location based unless you are using the term loosely (which is the only way I would imply that it is). However, since the upgrade to 10.6.1, I've had more phantom slowing (with and without engagement of the brake, sometimes harshly), seemingly targeting a vehicle intruding on my lane (when I took over, I got an FCW because it was heading straight for it), tons of non-existent vehicles in the non-drivable space on the visualization where there is nothing IRL (practically never saw that on any prior version), and random swerving on wide and clearly marked lanes where it never had an issue before (and even FCWs to go with that random swerving in one case even though there was nothing but clear road ahead [no trees, no bushes, clear painted lines, no changes in road surface]). That's certainly not an exhaustive list, but I think it's enough examples to illustrate my POV.