Both should serve you fine for those 20 years.

In theory...the painted cladding on the Ultimate is a medium that has a longer history than the colorant that is added to the Elevate pultrusions, however, we do have good data on both.

If you are concerned about insulation and energy efficiency, you might want to reconsider your choices. Marvin make nice windows, but the don't register anywhere near the top of the list when it comes to efficiency. When we have a customer that wants Marvin quoted, we give them an honest assessment of what to expect, and that does not include a supremely airtight window assembly.

As far as rotting, etc, that is going to be a concern with any wood interior window here in WI. condensation kills wood windows in this environment. If you are going with a white interior, there is no way that I'd recommend a wood interior window. Whether that means the Essentials (if you've committed to Marvin), or some other fiberglass, composite, or vinyl option.

On the exterior I wouldn't expect any issues either way, but on the interior, wood will require vigilance for it to last. We have some customers with busy households (never open windows, always either the heat or ac running) where we've replaced wood windows in 9-10 years. 20 years is certainly doable with maintenance, I would not expect to get to 40 years.