Basically... I admit I didn't get very far in it, but from the onset it seemed more like a Tom Clancy novel than Star Wars. Now I like in-depth details and stuff, but I feel they're out of place in Star Wars.

I read a lot more of Splinter of the Mind's Eye than I did of Heir (I think I got at least one third of the way through), but it had Luke and Leia doing stuff I didn't feel was very true to their characters--willfully letting themselves be thrown in jail without a fight, for example, instead of having an all-out brawl. The plot was also a little slow, and many of the concepts it advanced are things I just don't see in Star Wars. So again, it just to me felt less like a Star Wars book and more like a book that just happened to feature the Star Wars name.