2. Other side of the same coin: we haven't actually been able to see a white (vinyl) interior casement or awning 400 series window.???

You are going to buy the windows without ever seeing them. You are courting disaster. Even if you get great reviews, you really need to see them for yourself.
The 400 series has a vinyl wrapped sash to the interior with a wood frame. If you search the board, there are much better windows available. Andersen has the name and for many is almost a generic name for windows. I have had people ask about Andersen windows without knowing they were a wood window. Good luck but you really should look at the real thing. I can't believe a local HD doesn't them on display.

Have you looked at any of the fiberglass products?

We went through the Andersen/Pella/Marvin//fiberglass/generic decision process long ago and decided to go with the Andersens because the company has a reputation for standing by their product, they looked fine to us, plus both the contractor and architect recommended them.

But now that it's time to order the units, we realize that we have never seen casement or awning 400-series windows with vinyl interiors. We've been to multiple Home Depots multiple times, to two different "WindowRama" places that have pretty good selections of Andersen (and other) models to look at, and also went to an Andersen "super showroom." We've seen and carefully decided on what we want for the 14 double hung windows that we are putting in, and are not too worried about the eight clerestory awnings because they will be so high. There are nine casements, and the five that will be at eye-level in the kitchen are a major concern. As eastbay10 rightly indicates, we dearly want to avoid disaster, and if we can't see the units in person we're thinking we will have to get unfinished pine and paint them ourselves; that's time and expense we'd rather avoid. We're not looking for GardenWeb to make the decision for us, but thought it was worth a shot to see if anyone had any experience they could share with us.

I've been selling Andersen for about 7 years now and I wouldn't buy the vinyl wrapped interior if you need the window interiors to match because you can't paint it. The paint just won't stick to it. If they're in different rooms you'll be ok but if you have the casements and double hungs in the same room go with the clear pine and paint them. I saw that you also looked at Marvin, it can't be that much more money for the Marvins with all those Woodwrights you're getting. Marvin's a much better window than Andersen and the Woodwright to Ultimate Double Hung pricing is not that much of a difference.

Thanks, rsglazing, but I think we're too far along to re-look at the Marvins; the rough openings for the Andersen sizes are already done.

But the big news is that we went back to the Andersen super showroom today, and learned that we were just wrong about the white interior for casement and awning units being vinyl wrapped: they come "pre-finished white," which means factory painted. What is vinyl is the wrapping around the sash, but the design is such that very little of that is actually exposed to view.

So, sorry to say, but the original question was based on our having bad information. The good news is that the problem is solved. And maybe the discussion will help someone else in the future... at least until Andersen changes their product line!

Thanks to all for the helpful comments.

Sorry- That was a brain fart on my part, I knew that. I was thinking of their 400 series doors with the white interior and trying to paint over that.