On the plus side, runners should get good views of the city by going up Regents Road.
If the tramworks are gone by April and the Rock & Roll Half follows the same route as last year you can get pretty much the same city tour as the 10k, you'll just have to run 6 miles first (3 of them uphill!).
From memory, I can't think what bits of the city are affected by tramworks that have any bearing on the 10k route. It might be becuase of diversions indirectly affecting the ability to close roads.