I'm a hobby photographer. I do things semi-seriously, I usually don't use cheap equipment, and I shoot Canon (when I started Nikon had nothing like the 7D in a price I was willing to pay). I plan to continue shooting Canon and will be adding a full frame to my collection within the year.
However, my fiance has been using a point and shoot, but he wanted to get a more beginner level DSLR for himself. We found something in the Nikons that the Canon was lacking: a camera that still had scenic modes while still being more advanced than the cheapest start cameras so I'd actually enjoy using it. On top of that, I just don't want to share my lenses.
The D90 seemed absolutely perfect. Quality vs price (used) was definitely a good factor. We were 100% convinced that that was the camera he'd go with.
But I recently had my attention caught by the D7000, which while being $600 more expensive (with lenses) than the used D90 can actually compete with my camera on some level. This intrigues me, because would be a much more direct Nikon vs Canon comparison while still being lighter and easier to use for beginners (meaning it'd be great for traveling if we wanted something we could both use). At the same time, the D7000 is more of a "want" than a need and a D90 would fit what he needs perfectly while saving us a bit of money. I also don't know if it'd be worth getting the newer camera if we're just going to use cheap lenses.
I've typed out a pros and cons list, compared the hard specs and looked at performance comparisons. The D7000 is something I would love to have in my collection, but I'm not sure if it's worth $600 more, especially when I already have a camera that competes with it. Getting either won't hurt us financially, it's just a matter of worth. My fiance doesn't care which one we get. He'd be happy regardless.
The alternative is I force him to learn how to shoot manual and make him use my camera, but I've already tried that and he's slow. He tried the D90 out (our friend owns one) and really liked it, actually taking some decent photos, whereas when he uses my camera 90% of the photos turn out to be garbage. It might just be that the Nikon ergonomics work better for him.