Make sure you get a good subwoofer. It makes a world of difference for drums an bass. I have both bookshelf and desktop with a subwoofer and the subwoofer makes the base pop out more. The bookshelf monitors make vocals a lot more clear. For rap on the desktop speakers the vocals get mixed with the vocals.
I wrote about it before and compared it to my desktop speakers
Bookshelf monitors are much more flexible as you can add more speakers to a setup and have modular connectors (definitely recommend bananna plugs). I’ve heard some people who use bookshelf speakers as a center channel in home theater setups. For desktop speakers, if you want more, you need to buy a new set.
If you have a small desk and a big monitor, make sure to take the dimensions of bookshelf speakers into account as they may not fit on your desk/setup.