In reply to Alan James - Rockfax:
If you look carefully at the sole of the old Camp Four you'll see an area at the toe/instep which has no lugs and is similar to (not the same as) the Guide Tennie. The rubber in this area (which has a red symbol) is Stealth C4, the same as is used on the complete sole (as far as I'm aware) of the Guide Tennie. We all know C4, and Five Ten describe it as having "high friction and excellent edging". The rest of the sole is Stealth S1 (and has a yellow symbol), described by Five Ten as "ideal for hiking and mountain biking".
The sole of the new design is entirely Stealth S1 (which I'm sure will have reduced the manufacturing cost).
This is the point I was trying to make.
Your points about the lugs are interesting, and my own feeling is that if the deeper lugs had been added just to the heel area it would have improved the one weak area of the old boots for UK use, i.e. damp grass and mud.