"Others?" as in better than other tamas or other Virtual pets?
It's quite a bit better than the v3 due to the points system, I think. (I like the v4 more and more each day.) Regardless of it's comparison to the v3 or other past tams, though, it's worth the buy. Period.
As for other Virtual Pets, I can't say I have too much experience with them. Nothing except some older japanese VP have ever enticed me at all; I'm pretty tam loyal. ^.^
The v4 is worth the buy.