No speed limit. TACC is limited to 85,mph (used to be 90mph). Not sure if there are any other upsides.
I suppose its more peaceful if you're doing a few lane changes. TACC bings and bongs when you disable/reenable it. For some reason fails to do what every other auto manufacturer does with L2 cruise going all the way back to at least 2010 (my old Prius). Most cars auto-disable lane keeping when you put on a blinker, then after you're done changing lanes and turn the blinker off, L2 cruise auto resumes with no bings/bongs. In a Tesla with standard AP, you have to disengage TACC manually, change lanes, then manually re-engage TACC (each step brings its own bing/bong). Wakes people up if you're on a long road trip and that keeps happeneing.