I voted "average". The last third was an action-packed thrill ride, but there was a lot of underwhelming stuff as well. Data's being forced to torture Akharin, the contrived situation where Data had to choose who to let die with the split tractor beams and the comically stupid
TEN HUNDRED VAGILLIASQUIALLIAKABILLIAKAKILLION DEATHS. Hundreds of thousands of galaxies. With no sense of scale and very little sense of urgency. If the entire book had been about saving Wesley's mushroom alien friends and their planet, would it have made much of a difference?
That Data got his wish at the very end was unexpected and nice.