Quite agree it's been done to death about 'level by's. Had never considered that if you were on a heading you would think the speed restriction wouldn't apply unless explicitly stated. Considering the amount of headings used especially in and around the TMA that might make for slightly more RT if we were to have to reiterate the speed limit. Possibly not such a big deal for LL arrivals, as you'd probably be own nav to hold by 12DME (hopefully?) but for example for SS/GW from the north, SLP is CLIPY if I remember correctly, and you're virtually always on a heading past CLIPY. So if you're on a heading, and believe the SLP doesn't apply, when, if ever, would you slow down?