Thanks for asking! I'm of the opinion that if the model is wearing boots, then she ought to be wearing BOOTS. Take the Bo Derek example, those boots may not be "classic jungle boots" but they're real feminine boots that are hot. I would say that wearing combat/jungle boots doesn't count as boots, just like hiking boots are really shoes that just cover the ankles. We might as well be asking what kind of shoes we'd like them to wear. I get disappointed when hiking boots get tagged as "boots" for videos because I think for those of us who are into boots (Bart and others please back me up here...) that hiking boots/low height combat boots don't count.
Realism isn't a big thing for me. Consider that a lot of TV/movies with QS scenes have crazy outfits in them. I can accept that if we're watching a video, there is a little suspension of disbelief going on. Partcularly true for sci-fi/fantasy type shows.
For boots, I think they need to be at least calf/knee height (and even higher is great too because you get to see them longer in the sinking). I'm not saying they should always be stripper-like with crazy heels (and personally I'm not a fan of high platform heels because I do associate those with strippers), but I think in general boots should be high. That's why they are boots and not shoes. Heels can be reasonable (high or low) as long as they're high boots.
And since the boots are on women, I think they should be feminine. Even Hunter rain boots look feminine. Masculine type boots on women (e.g. combat boots) tend to diminsh whatever sexiness was there. If we're going to be looking at hot models, why are we trying to give them male footwear? Heels can help feminize some (okay, a lot) but also just a good fitting shape/cut can do that too.
I think Bart posted some good examples of boots and I agree with him on that (bondage still optional
).I'd add that if you're looking for new ground for women wearing boots in QS, I think anything in the sci-fi/fantasy genres would work. We've got a lot of modern day stuff, and a bit of pirate stuff, but fantasy (e.g. Conan to Lord of the rings) and sci-fi (anything futuristic) is pretty untouched. And boots are not just appropriate, but are really the norm for these genres. Just a thought.
Again, much appreciated that you solicit our opinions on this!
Rusty
And high heels, shiny model boots and dramma sinking are not im taste. 
