lip service can do some sculpting and texturing but thats not really where its strength lies.
its strength is in deformation. it has a very comprehensive toolset of pose space deformers which is pretty amazing. you can do some similar things with comets pose deformer which is free, but the interface is awesome in lipservice, plus lipservice is more than a one situation tool. it doesnt just do skin deformations after animation it also lets you do facial animation and all kinds of stuff.
i think its a must have tool for maya to be honest with you. softimage has a lot of this stuff built in, but the interface and ease of use of lipservice is pretty impressive, although i found it a bit unweildy at first when i was using the demo…once i got the hang of it i was thinking it was a game changer for maya
so yeah you can do some texturing and sculpting but thats not the reason to get it