What is the difference between the studio monitors and normal bookshelf speakers? I see most of the ones you listed have bigger woofers.
The biggest difference is that most good studio monitors have an even sound power response and treble/bass adjustments for different room interactions.
That's not set in stone, and there are both mediocre studio monitors and world-class bookshelf speakers, just like there are world class studio monitors and crappy bookshelves. Actually, they really should be one and the same when well designed. However since they are sold through different channels and marketing, aesthetics and features will of course vary. Among my dream speakers though, are a pair of Genelec 8260A studio monitors. They're not pretty but they are an engineering marvel.
Interstingly enough, I was walking through the new digital library at my university, and they are now using the JBL LSR monitors.
Anyways get whatever you feel comfortable getting, as long as it's good. But the LSR 2325 or LSR 2328 would definitely be among my suggestions
Would a pair of the JBL's sound better than a pair of B&W 685's or Dali IKON 1 Mk2's for example? What's the difference?
They will sound more accurate to the source material, because they measure more accurate. Whether that sounds better depends on whether or not you like the source material in its actuality.