In reply to sam_craddock:
I've had my Nepal's since 97 and from my experience the most important question to ask first, is what condition are the bails at the front of the boot?
Once you know this question then you can fine-tune your choice of crampons.
I only mention this as the condition of the bails on my boots had a significant effect on the fit of my crampons. I have two pairs of crampons, some CAMP 12 points with straps dating back to 1995 and some step-in Sabertooth's, with no front strap, going back to around 2000.
The ancient CAMP crampons fit perfect and are my fallback crampon when things go wrong.
About 7-8 years ago I was on a route on Anoch Mor, and nothing fancy, possibly up to Grade III if that. I was kitted out in my boots and Sabertooths. Back then the boots were quite old and the bails had worn down considerably and only stuck out only a couple of mills.
As my Sabertooths were step-ins and had no front strapping I discovered half way up the route that one of the crampons kept falling off. Not exactly a good thing to happen. After a lot of faffing and worrying about my predicament I bodged some 6mm cord around my crampon and boot so that I could finish the route and get off the hill.
Suffice to say I got my boots re-soled ASAP after that.
I don't know about the quality of crampons today but my advice would be, that if you choose step-ins then choose a pair with some sort of front strapping method just in case the crampons slip off your front bails.
Otherwise, I have never had a problem with any crampons fitting my 16 year old boots.