From their own website:
Glass fibre - Diolen
Our most widely requested option balances weight, stiffness and durability. It offers superb impact resistance and can be easily repaired if damaged. The deck is also glass fibre with added reinforcement around the cockpit (for deep water rescues) and footrest mountings. It offers superb resistance to impact, abrasion, puncture and tearing. Our toughest, stiffest and most durable construction, suitable for the most challenging expeditions or hardest working coaches.
Our Kevlar carbon hull construction is lighter and Our toughest, stiffest and most durable constructionmore resistant to puncture than our diolen glass fibre construction. This construction adds kevlar Carbon to the hull and combines glass fibre and kevlar carbon the deck making the finished product around (3lbs/1.5kg) few kilos lighter than a glass fibre - diolen kayak. A great combination of lightweight, strength and rigidity.
Lightweight Kevlar Carbon
Using even less glass and replacing it with more kevlar Carbon this is the ultimate in lightweight hull constructions. Saving approx. 4.5lbs/2kg over glass diolen - Some durability and stiffness is lost compared to a heavier construction due to the reduction in materials used and we recommend a keel strip is used with this option.
I have a 2003 carbon kevlar Capella. Other than a tree landing on it during Frankenstorm Sandy and putting a couple holes in it, knocking out a bulkhead, the coaming eventually popping loose, etc, which I had repaired by a local guy for a few hundred bucks, she's held up well under normal use. He didn't seem to take issue with the material as far as repair work is concerned. I do a lot of surf paddling in the Capella, so I think after 10 years, I can say the P&H carbon kevlar hull has worked out fine.
He builds kayaks and canoes, and seems pretty knowledgeable about the materials. He talked some about seeing very pretty carbon boats built with a low grade, low modulus carbon that he felt was inferior. He wasn't referring to P&H.
He didn't get the carbon/kevlar weave. He wasn't sure how the different properties of the 2 materials weaved together like that would compliment each other. He liked the idea of layers vs. a carbon/kevlar weave.
A friend had picked up a carbon/kevlar Pilgrim about a year ago, and a typical bump from another kayak practicing rescue stuff put a hole through it. Quite the shock and disappointment. My friend thought the carbon/kevlar just wasn't up to the task. And it's hard to argue in that case.
But I've taken quite a share of bumps and tumbles in the Capella with that carbon/kevlar weave construction, and other than a tree falling on it during a hurricane, she seems to be holding up.
"Our toughest, stiffest and most durable construction" is about all I need to get from the manufacturer to choose fiberglass/diolen for myself if I were just to choose. But they've proven to me that they make a good carbon/kevlar product that stands up to a decade of use so far.