I never used Pella due to budget limitations but coming from a place that often has + - 30 degree Celsius swings in temperate and often extremely quickly, I have never experienced, nor seen evidence of vinyl windows having shrinking issues. In fact, that is the first time I ever heard anyone mention it.

Not saying it isn't a real phenomenon, just that I have never seen it as an issue.

With great power comes Awesome irresponsibility.