My 2 cents worth,
I probably would do the trade for a loaded NEW Wing, but then I'd sell theWing and buy another used RSV (they're such a great deal on the used market), and maybe a nice used Victory with whatever was left over.
I've looked into Wings in the past, and no doubt, they are awesome bikes. But my issues with them are:
When I sit on a Goldwing, I feel like I'm sitting in an Accord, not on a motorcycle. To me motorcycling is an awesome visual experience, I don't want to look at a bunch of plastic and automotive looking guages.
I don't like saddlebags that open out. Unless you use liners, when you open them up everything will fall out.
I always get low to mid 40's mpg on my Venture even with my wife on the back and a full touring load. Wings seem to only get mid 30's.
Another big thing, I like to shop around and buy nice used bikes and let someone else take the depreciation hit. Ventures are an awesome deal on the used market, and come very nicely equipped. Goldwings are very pricey on the used market. I think that's mainly because of the "herd mentality". Most people in the market for a touring bike that don't buy a Harley will automatically buy a Wing, just blindly following the crowd.
A lot of what is standard on a Venture is optional on a Goldwing. My buddy's wing doesn't have a CB or a 12V charging outlet! (Of course it doesn't have a cassette player either). But who cares with mp3, Pandora internet radio, etc that you can play through your phone and the accessory jack!
And finally, I know the wing is probably a little faster but come on! How much speed do you need! A couple days ago my wife and I were with a group heading back to Orlando from the Keys and we got a little behind from me taking it a little too easy. With just a little twist of the throttle we went from 70 to 95 mph, in seconds, with no vibration, no drama, easy as falling off a log.
Yes, I'd take my Venture over a Wing anyday!