I'm a huge fan of the Historicals. At the very least, for being a solid foundation and reference point for new story arcs. With the newer products correcting or retconning problems with FASA products, the writers have readily accessible vetted text at their finger tips. Remember, the latest book is considered the de-facto authority on a subject, so the more Historicals, the better for a consistent story.
People may whine about retcons or the older books, but FASA wasn't big on fact checking or consistency. Looking forward often means spending a little time cleaning up the past.