In reply to Gordon Stainforth:
> I think you've got to be joking.
I fear not - I've only been on the Pike twice, once by the Langdale route as per the OP's query (in May 1983), then in June 2002 from Coniston. I've got timing notes for the latter day - went Old Man (by the southern shoulder), Swirl How, Great Carrs, Cold Pike, Crinkle Crags, Bowfell, Esk Pike and then Scafell Pike. Got there in 6hr 51min including 48 minutes of lounging, so a not-too-long six hours in terms of actual walking. Came back via Broad Crag and Ill Crag and down to Langdale, and would have been happy enough walking back via the roads - nice sunny evening - but in the end phoned from the ODG (didn't have a mobile back then) and was collected by my better half's late father somewhere near Chapel Stile. That was after about 10 hours 15 mins, so the whole thing could have been done in about 11 hours 45 including loads of stops - a long day but not ridiculously so in good summer weather.
Re the OP's question about how long from Langdale, on that day - in very dry summer conditions - it took me 2 hours 50 mins back from the Pike to the ODG, via the two lesser summits and including 15 minutes off in Rossett Gill, and with probably a few other short stops along the way.
I've also climbed High Stile from Coniston - on a stupidly hot day when I was OK (or so I thought) until Sty Head, then began to struggle badly with dehydration and almost keeled over. I've never been so aware of Ronald Turnbull's astute observation that "dehydration doesn't feel like thirst, it feels like tiredness". Gable was very hard work and if I hadn't met a friend on Brandreth I wouldn't have managed it. The stretch over Haystacks was a fuzzy blur. Got a lift back from Buttermere and had to be put on a tea drip for the rest of the evening. Another memorable day, though - you have to do these things sometimes.