Actually, Sierra Pacific makes very nice windows, well priced for being completely custom. My husband, an architect, has used their windows in very high-end homes in extremely demanding environments (eg., high Sierras) with no problems. We bought them for our home and I'm so far very happy with both the process (lots of changes until we said, "Go!") and the windows themselves. For the same money as some others offered vinyl clad pine, we have vertical grain fir double-hung windows clad in aluminum, with as well-performing glass as you can get at outside of the zero-net windows (which are incredibly expensive). Several experienced tradesmen who came through our build after the windows were in remarked something like, "Those are some really good windows you have." Their casements are particularly nice (we have a couple of these).

I'll let you know in a couple of weeks I just purchased SP for the front (historic view) of my home. Candidly - if they fail 5 years earlier on average, I make out significantly better from an expense standpoint. The first quote I had from Pella and Marvin crested $40K (not a lot from some perspective, enough to make me reconsider life) I shopped and researched and settled on SP - backed by a 20 year warranty for any wood rot on their clad window and backed by a very reputable and financially strong local dealer. I finally through caution to the wind and went with builder grade rear facing windows and could not be happier - they are architecturally consistent and backed by a so so warranty - at the price installed ($4000 for 11 windows) I am thrilled with the cost benefit ratio. The SP are significantly more - but by mixing the two brands I saved $30K and can do it all again in 15 years if need be. Good luck sounds like a fun project.

Moisture between the glass would not be caused by poor installation. Rather, it would be caused by a defective manufacturing issue or due to some type of unusual situation where the normal wear was affected. For instance, extreme variations in temperature due to orientation or something going on regarding the interior of your home. I design and specify windows for homes in Florida almost all of them on the water or close by. Sierra Pacific offers a 30 year warranty on its 2605 finish and 20 year warranty on its patented Coreguard wood treatment and I would consider those windows. Andersen performs well too but they reduce their 20 year warranty to 10 years when on the coast. In my 40 year career, I have had great success with Andersen and SP and would run away from Pella if you are looking for an aluminum clad wood window. Just my opinion based on more than a hundred installations.

@bitterrootjohn I am wondering how it went with finishing the Sierra Pacific casement windows. Our painters just finished and ran into trouble. Although they protected/taped right up to the trim, the window trim itself is not tightly sealed to the window and the stain/lacquer dripped behind the finish trim that is painted black. It seems like Sierra Pacific would take some responsibility but right now it is all on our shoulders.