hey guys. sorry for the delayed reply. work has been crazy.
well, i skied my new skis last week and this past weekend. they delammed after one day. in fact, they delammed before i even skied them, after a few flex tests, but skiing on them didn't make matters better. okay, so how do i define delam? well, for me it's any sign of separation between the materials, mostly due to intentional 'hard' flexing and use. i don't really count 'chipping' as a delam so much, but it depends on how the chip was created, etc. although chipping can be something that creates a weak spot which causes delam. anyway, i'm very picky about my skis and how well the materials bond, so any slight hint of material separation is pretty much considered a delam to me. some of my skis have a little delam but they don't get worse. for example, i've put in about 25+ days on the Bangers and they seem fine.
but most of the delamming i've experienced is between the edge and the rubber/glass layer. the delams mostly occur at the tips and tails, often around points of high stress, like the ends where the skis get banged up or around the curvature where there's 'stored' energy like a compressed spring. the delam may not be readily noticeable, but it's there. my latest skis have Ptex sidewalls and the delam is between the glass layer and the sidewall material. everything else is fine. i know what caused it and it's poor preparation of the sidewall material. after i flashed the skis, i flexed them and heard the familiar sounds of materials 'shearing' apart. i looked more closely at the sidewalls and noticed the separation. i haven't noticed the separation as much with wood sidewalls because the wood bonds well. i've been trying a number of techniques to improve the boding of certain materials, especially ptex. some of my skis survive about 10 days of ski touring before i notice the first sign of delam, but again, the delam may be small and it may not propagate. still delam though.
someone asked about whether i've broken commerical skis before. well, i'm not an abusive skier or any harder than the average skier. but i have broken about a handful of skis. one pair i broke on the first day after making the second turn! they were a pair of RD Valdez Extreme downhill boards (212 cm length). granted i was going a bit fast and out of control, so on the second turn the front end of my right ski folded into a 90 degree angle and threw me like a rag doll. luckily i was not harmed. i immediately took the skis back to the dealer and they were surprised to see it broken and were happy to give me a new pair. i just bought them the day before and they were on sale. i've bent a few other pairs in a similar manner (PREs and Rossi skis), and i've experienced delams in the Volant skis as well as a couple pairs of K2s. so normal skis also delam and break.
most of my skiing is touring and the snow conditions can be interesting, but i don't think it's too much harder than say park riding. here's a photo of me skiing on my new skis last weekend taken by a friend. i skied pretty much until the snow turned to grass and dirt (about another 300 vertical feet). i only managed a few stratches on the base material but they were quickly fixed on Kelvin's wet-belt sander.
i'm going to take some photos soon of the delams on my skis so we can continue this discussion and maybe compare with other home-built skis.
Little Kam's Ahmo's which experienced 130+ days held up well, so it would be interesting the see the photos.
BTW: plywood, is this the picture you were looking for?
so i somehow understand that skis only last 10days. 
... not any more though. I only got to ski 10 days or so last year.