In reply to Mick Ryan - Editor - UKC:
I wouldn't want to argue with a guide, but my experience in Scotland and else where of both Warthogs and "ice" hooks is quite different. I used to climb a lot in the Southern Highlands and Arrochar and there everyone took and used warthogs regularly (pre-ice hook era). We generally carried two. Now these days it seems hooks are deemed to be a replacement - although it seems there is no empirical research and precious little anecdotal evidence as to whether they are better, worse, or the same as warthogs in frozen turf. But I remember belaying off a warthog on the Cobbler when all else I could find was a small and not very deep knifeblade (my partner decided to take a factor two fall onto the belay leading the next pitch, so that belay will be imprinted into my memory for the rest of my life), and many times using them when you arrive on the top of a cliff where you are suddenly in a flat, frozen field with nothing to belay off - Udlaidh, Beinn an Lochain, Lochnagar being good examples.
You have to be really desperate to put ice hooks in ice - I've done it but generally it strikes me as too much hassle. But for turf - and something else the article doesn't mention - using them in rock - they are really good. For rock obviously you can use them as giant sky hooks if nothing else is going to work, but they can be placed in lost arrow size cracks as well very securely.