To amplify Denti's point about knowing "how it behaves if you come close to the lower speed limit", I know the days of flying correct speeds on finals are fading, but it was once the thing to do and it was by no means unknown to have the A/T rather unhelpfully 'cut-in' during a landing. There are some weights for a 737 where, particularly at F40, Vref+5 is actually just below or equal to 1.3Vs, at which the A/T mode described operates. The nett result of that is that an ACCURATELY flown Vref+5, and the start of a flare just a tad above 27'RA, and off we go
Hours of fun and much entertainment for PNF........