Huge Improvement
All of my manifolds are designed to be protected from the sun by either a fake rock or storage box. Putting in SCH 80 risers still leaves the valves exposed so there is no point in wasting the money. Far better to protect everything.
Before you start in about how you would've put in a backflow and in-line valves... this is California and the job is to rebuild it not redesign it. This is up to code and yes I'm sure....