I've had a CI Remix for my "main board" since March 2012. Its been to Costa 3 times in that time. surfed every spring, summer, and fall swell in Jersey we've had (doesn't float me in my 5/4). It is the ultra light glassing.
I don't have a single pressure ding in it along the rails where I hold during a duck dive. A surprisingly low number of pressure dings on the deck, and everything else is like new. I am extremely surprised with its longevity, considering how hard and frequently i use it.
Also nailed the reef at Negra on a duck dive, and the two dings on the bottom were minor, and the damage stayed very local (no cracking or spreading from the point of impact).
I understand that every now and then someone gets a bad apple, but when I hear of people bashing the glass jobs on a CI I laugh. This isn't my first CI, and most of my friends ride them for this same reason. If you take care of them, they can take a beating.
It depends alot on which company glassed it. They use a variety of different glassers and of course quality can vary board to board.
I got an Semi Pro 12 last year which was glassed by Mystery Glassing and the glassing flat out sucks. I'm not hard on boards and often keep a shortboard for 2-3 years and get rid of it only because I want something different.
The Channel Islands gets dings if you breathe on it. It's got tons of pressure dings in the bottom from I don't know what. I use it as a travel/step up board and everytime I take it out of my boardbag after I get off a plane it's acquired some new, significant dings generally requiring immediate fixing before I can surf. Other boards in the same bag hold up fine.
If you are buying off the rack and it has the Mystery Glasing laminate on it, don't buy it. I love the board but if I got another I'd probably custom order and specify another glasser and probably a heavier glass job. It's a shame because it's a really good board and works great in hollow head to double overhead surf.
Kinda stinks. One time I was carrying a bunch of stuff to the beach (including board) and my board slippeed out from under my arm but I caught it with my knee. When I kicked out of a wave later, I looked at the bottom of it and there was a huge pressure ding on the bottom. I have ultra light glassing because that is all they offer at some shops.
Glassing is only part if th problem...the real question is the blank and who is cutting/scrubbing it. Blanks are typically denser closer to the surface of the blank. todays foam is gret stuff, but you can still overshape/cut. If the foam was over scrubbed or cut a bit deep/blank in correctly placed on machine high or low, etc...it'll be softer and more prone to pressures.
A glass job is only as good as the core it's protecting. I've had double 4 decks hold p really well. I've had 6/4 decks pressure heavily, etc. all depends.
However...I agree with robgnyc...it does depend on the company for polys. I've had boards glassed by the Lab that were great, others...meh. I still think the foam issue is more a concern for me rather then the Glassing...
if you *really* want a CI & you don't care about a little extra weight, order it custom & get their "standard" glass schedule. it'll be done in-house (unless you request otherwise) where they keep a closer eye on QC & the glassing is a bit heavier: 6/4 on the deck, single 4 on the bottom.
if you're a smaller or lighter guy, the stock ultralight (which is what they do on every board under 6'6") is ok. but if you're getting up over 170-180lbs, you're probably gonna want a slightly heavier glass job.