These are some great racks! :P
No, seriously. I've got my monitors on top of them without any issues, as well as items mounted into them. The look matches my table which is perfect and as it comes in different colors you can use whichever one suits your setup.
Only downside, like any racks I guess, is that it is a m*****f***** to mount things into them, but once the hard work is done you got yourself some nice looking racks for your equipment.
Excellent if all you've currently got for your studio is a flat table.