I tried the "Killer B's" Foundation trilogy, but didn't really enjoy it. Asimov left the Foundation novels in the middle of the Interregnum, with five centuries worth of history to cover before the establishment of the Second Empire. Why did the authors feel the need to cover Hari Seldon's life again
? It seemed a missed opportunity to me. Five hundred years free to explore, and they retread well-covered ground.
I really love Psychohistorical Crisis
. It's a great homage and though not technically set in Asimov's universe, it's a great story. Some people might think it bogs down a bit in places, with too much exposition about mathematics (among other subjects), but I enjoyed every bit of it. It took me years to find a copy, though.
I thought the stitching of the Robots, Empire, and Foundation novels worked pretty well. I enjoyed seeing the long spans of history that Asimov covered, over 20,000 years. Despite all the novels, they still only built a thumbnail sketch of a Galactic society, and I would enjoy reading more stories set in that universe, especially if they are of Kingsbury's Psychohistorical Crisis