I take both crampons and spikes on winter outings now. For instance I used my spikes to go up the long SE slope of Beinn a Chrulaiste on Sunday. It was safe enough (I could feel the spikes digging nicely into the crust on what turned out to be a fairly steep gradient) and in hindsight I could have used crampons which I changed into for the descent on the other, less steep, side. However the day before I had the crampons on all day to climb up to Stob Coire Sgreamhach via Sron na Laraig, but changed to spikes when we got to the floor of the Lost Glen - it was icy but not steep and there were patches of black ice on the path. My companion slipped on black ice beyond the boulder field, so I was glad of my extra grip. I had experimented with this dual approach coming off Stob Dearg (Buchaille) the year before. Changed from crampons into spikes when the gradient eased in the corrie. So horses for courses, rather than weight saving.
John and his trusty companion Moss embark on the Cape Wrath Trail, starting from Fort William and ending up in the far north of Scotland at Cape Wrath. The route is approximately 230 miles long, unmarked and you have the Scottish weather with which to contend.