I think it's mostly aimed at visual media composers. It basically gives you a bunch of hi quality grooves which are unique, yet organic sounding.
There's a lot of variety, and of course in RMX you can combine the individual elements with elements from the core library and other expanders you may have, let alone do a TON of other cool things with them. A lot of the elements also lend themselves well to chaos designer applications.
I agree, liquid grooves is probally my favorite expander, lots of acoustic sounding kits, and yet electronic mixes in there as well, a good mixture that really is versatile. this is the one I find myself drawing from alot. you will really dig it
Liquid Grooves is a fantastic expander. I bought the ROM version a long time ago and as soon as the RMX expander was released I bought it immediately. Also, it's a great expander to mix and match with the Metamorphosis Expander.