In my opinion the difference between floorstanders and bookshelves (and I mean real bookshelf, not any speaker that sits on a stand) is a matter of taste.
Whilst it may be true that a similarly priced bookshelf is of higher quality (and this is not always true because not all speakers are well designed) your personal taste may be, like mine, that music simply isn't enjoyable without a decent bass response going down to at least 40Hz, no matter how pure the midrange, or crisp the treble.
So I think your question has no answer because it's a matter of your taste in music and your taste in sound reproduction. Some people can live without the bass for a better midrange and treble, and others cannot.
As others have mentioned stands are important, and often when these are factored in (Several hundred dollars) then the bookshelves are similarly priced to the floorstanders.
As for full range speakers versus bookshelfs and a subwoofer I would say that, again, there are no absolutes. I have heard very good and terrible floorstanders, and very good and terrible sub+sat combinations. The one advantage of sub+sat systems is that they can be easier to place in a room, placing the satellites for imaging and the sub to load the room. However good subs are expensive and often drive the total cost above that of a floorstander.
Whilst it may be true that a similarly priced bookshelf is of higher quality (and this is not always true because not all speakers are well designed) your personal taste may be, like mine, that music simply isn't enjoyable without a decent bass response going down to at least 40Hz, no matter how pure the midrange, or crisp the treble.
So I think your question has no answer because it's a matter of your taste in music and your taste in sound reproduction. Some people can live without the bass for a better midrange and treble, and others cannot.
As others have mentioned stands are important, and often when these are factored in (Several hundred dollars) then the bookshelves are similarly priced to the floorstanders.
As for full range speakers versus bookshelfs and a subwoofer I would say that, again, there are no absolutes. I have heard very good and terrible floorstanders, and very good and terrible sub+sat combinations. The one advantage of sub+sat systems is that they can be easier to place in a room, placing the satellites for imaging and the sub to load the room. However good subs are expensive and often drive the total cost above that of a floorstander.