Thanks all for all of your helpful comments! I haven't said anything because I really want to be a listener and learn as much as I can!
TaftCoach, I love your idea of downsizing now! In fact, that's what we're in the process of doing. We've boxed most of our things and have started living with small amounts of clothing and kitchen gear to become adjusted to the change.
Many of you have suggested getting a larger model and perhaps not a hybrid. While I love the 17xfd, I can be convinced otherwise, mostly if you play the safety card. Is there another model you'd recommend? I'm a safety nut, and I like the idea of pulling something way smaller than what our Toyota Sequoia 2008 can handle. That is a significant draw for the 17xfd because it's light and short. That plus a good anti sway (I'm leaning toward a Pro Pride), makes me feel like we'll be pretty safe on the road (along with keeping an eye on the tires and all of the other essentials). I also like that the three open beds create mini "rooms" that the kids can use to have separate space. With the bunkhouse models, someone still has to sleep in the "common area" (i.e., sofa or dinette). I'd definitely be wary of staying in a hybrid in a Cabelas/Walmart parking lot though and love the appeal of being able to turtle.
Thanks again so much for all of your help! We leave at the end of May and are in countdown mode now, so I'm sure I'll have more questions as we get closer.