Well, first, I think this could be a great opportunity to read the great English novelist again, whose best novels are some of the most dramatic and compulsively readable of the 19th Century. I think of him almost as I do E.M. Forster; they have little in common, but both wrote overwhelming literary page-turners.
As to the bios -- Claire Tomalin's book is "effortlessly readable," but lacks "intellectual meat." Ralph Pite doesn't have Tomalin's literary gifts, but seems to have more to say. Both get things wrong, both bypass unchartered territory, neither will make anyone forget Michael Millgate's definitive life. Jonathan Bate, no slacker himself where Hardy is concerned, closely scrutizes both.