Thanks for all the opinions. I've got a lot of parts on hand that I could use to upgrade the Santana, but there are still things I'd need, like a new rear wheel, or at least a new rear hub. The cost of upgrading is a small factor but not huge; I'd pick up parts as needed as I find deals and upgrade at some point down the road.

I was able to take a look at the Burley today (didn't plan to until tomorrow) and it looks nice...better cosmetically than the Santana, and I do like that it doesn't need any upgrading. It seems like it might be a better fit for my wife (biggest factor of course), but we'll find out tomorrow. We're going to test ride each, but as of now I'm leaning towards the Burley. Turns out that the price can come down to be about the same as the Santana. The seller also has a couple of Selle Anatomicas that can be negotiated into the deal, so we'll test them out with that as well.

All in all, it looks like the Burley might be the way to go.