Good picture, thanks. One other aspect of the whole summit-cairn debate is that it can be rendered rather irrelevant in winter, when either the cairn is buried or - in a few instances, eg Sgor Gaoith and also Beinn a'Chaorainn above Loch Laggan, the cornice has a habit of building up and creating a seasonal highpoint along the lines of the Galdhøpiggen / Glittertind debate. (In such instances trying to get to the on-the-day highpoint might be a rash thing to do.)
Also re cairns, while I'm no fan of over-cairning I tend to get more annoyed about the reverse side of the argument: people who trash old and perfectly worthwhile cairns just because they're feeling righteous or have had something dodgy for breakfast or have been reading too much McNeish. At least if people are going to do such things they should do it properly, but I've quite a few times (especially in the Ochils) come across cairns that have been taken apart and then - because the person who has done it is plain lazy - the stones lobbed about ten feet away. I tend to rebuild such cairns, but if the stones have been lying there for a few weeks there's the "gaping hole" problem that ronofcam mentioned. If people are going to do this (not that I want them to), they should try and either leave the stones in a stony place or - if it's grassy - carry them a fair distance away from the original site.
There's also the thing of people trashing old cairns that are either actual antiquities (eg the Helen's Muir one on King's Seat Hill in the Ochils) or useful / much-loved landmarks, eg the stone men on Geal-charn at Drumochter and the three tall cairns on Ill Bell in the Lakes. Thankfully both these latter groups of cairns seem to be gradually being restored (until the next time).
