I ride about 6000 miles a year. I'm thinking of Mavic open pro or Ambrosio Excellight. Is there much between them, and Ambrosio very durable (read on a forum about them cracking round the eyelets)? The front wheel is radially laced.
The Ambrosio seem good but we haven't been selling them long enough to say how long they will survive, maybe 1 year or so. None have failed so far. For what it's worth, in my experience most rims will crack around the eyelets eventually. Certainly it's the case with Mavics. I would consider the Open Pro to be very similar to the Ambrosio Excellight; they are a similar weight and they feel very similar to build - fairly flexible but build good wheels.
If it helps, we have a pair of wheels built with Open Pros which we've been riding about 5 years now, on and off, and they are still in one piece so I guess they are pretty durable. I am currently riding Excellights but have only had the wheels about a year and I don't get to ride the bike very often (I have to test a lot of different wheels).
Another good rim is the Velocity A23. It gets around the eyelet cracking by not having any. This scares some people off it but in my experience eyelets don't seem to add that much to durability, as long as the rim is designed and built right. None of the Stan's NoTubes rims have eyelets and we've built many thousands of them up, I've seen maybe 2 or 3 cracked under extremely heavy use.
Sorry if this isn't much help.... I guess I'm saying it's hard to pick the most durable rim out of a good bunch. We don't have any significant number of failures with any rim.