In reply to TobyA:
Hi Toby, yes, it was me that wrote the Climber article. I really hope I didn't come across as trying to suggest that manufacturers are guilty of fiddling the stats. I have no reason to think they are at all.
The problem is that the stats bear little or no relation to real-world experience. Taking weights as an easy example, I found that the weights weren't in proportion to the quoted g/m at all (like you, I didn't expect a 60m rope to be 60 x measured g/m but I did expect rough proportionality). I had a rope measured at 65g/m weighing less than another quoted at 63g/m. So, everyone like me that was anally retentive about getting the lightest gear could be getting misled by the figures.
I'll stop banging my drum but if you want to have a look at my data drop me a private mail.
Incidentally, pretty much all manufacturers cut 5% long so a '60m' rope will come out of production at 63m, plus or minus tolerance. As you point out, that tolerance may not be great.