I don't recall ever stalling on account of hill assist, but it was noticeable to me. What bugged me was the slight hesitation when starting on a steeper incline and the inability to drift backward immediately (to make more room for another car pulling into a drive as I'm exiting, or to coast out of an inclined parking spot without going into reverse). Maybe it was more noticeable since my other stick shift car doesn't have it, and none of my previous manuals did either. It was a very minor annoyance for sure, but it was nice to be able to turn it off with two minutes of coding.