I went through this same process several years ago. I looked at just about every cellular pvc product out there and evaluated them on numerous criteria. Koma was ruled out early, as I needed a material that could be milled, not just dimensional trim boards. Ultimately, the contest for me was between Kleer and Azek. Both companies are reasonably local. I always try to support local/regional/domestic... Azek is based in PA, where I was born and raised and Kleer is based in MA, where I ultimately settled. Honestly, my first call and tests were with Azek; at the time they were 'hands down' the market leader while Kleer was basically a brand new company. The particular project that I was gearing up for was a big one and demanded the absolute highest standards in craftsmanship, durability, and longevity. Additionally it was probably the highest profile project that we had taken on to date. If I was going to use cellular pvc, it was going to have to last. Like most of us, my teeth were cut over the last several decades mastering the use of wood in myriad contexts. I know wood. I understand wood. Every board is more or less predictable by species, moisture content, grain, grade, etc. This PVC stuff really felt like a gamble, but one which seemlying offered huge upsides. Between my company and several other contractors in my area, there was a wealth of local knowlegde, born out of our collective experience installing cellular pvc trim as typical replacement/substitute for primed pine or painted western red cedar in the most standard and straight forward of applications. Going to the next level required, for me, refining my understanding of cellular pvc. Just like wood, Cellular PVC's durability, longevity and appearance is just as dependent on the raw material as it is on the craftsperson(s) doing the installation. Switching from, in this case western red cedar to Cellular PVC was going to require support from the supplier. This is where Kleer dominates hands-down. I was invited to tour their plant, meet with their head engineer, had and have frequent visits to my sites by the regional sales rep. The access to Kleer's people, expertise and support is second to none. Beyond that, Kleer recycles all my scraps and the PVC saw dust produced in the milling and installation processes. This is a big sell for my clients, most of whom want a green product. Since switching from Azek, we have installed literally 1000's of square feet of Kleer. I made the right choice and I do not regret it. If I figure out how, I will try to post a few pictures.