I have a PC using the Sentience and Animation lists to very strange effect, not exactly as designed. He has a habit of making things sentient so he can interrogate them instead of studying them like a normal mage. Sometimes this is pretty useful and sometimes it is a bad idea, for example when the item is a 50th level artifact capable of summoning.
I'm not so keen on PCs creating things that are limited only by time and money. It's hard to meter out how much of those things they should have. I prefer setting those limits by level. They do have an animated, sentient wagon though, and a couple of acquired constructs.