This is another in the line of 'Heritage' novels that started, for me, as one of my weekly paperback fixes in my late teens / early twenties. I picked up 'Summertide' and really enjoyed its mix of characters, settings, and exploration. The strengths of that novel seem to have waned with every following book, however.
'Resurgence' is a difficult read. The characters seem to have bled together to a degree (the unique 'voice' that each character had in the outset is harder to find), and without the characters doing their bit the plot founders into territory where the characters play a passive role and simply get whisked from one situation to another.
That said, Sheffield's work remains as imaginative as ever, with interesting concepts all over the place. And the epic sense of the universe in which the story is set remains intact.