FranklyWeight is a structural question
Concrete tile is substantially heavier than composition shingle. Moving from shingle to tile can require structural evaluation of the framing. Any contractor proposing that switch without addressing structure is skipping a step your building department will not.
Going the other way is easier, with caveats
Tile to composition removes weight, which is structurally simpler — but it changes the look of the house, and in many Orange County developments that runs straight into association rules.
HOA and neighbourhood consistency
Large parts of the county sit under associations with architectural standards on roof profile and colour. Check the governing documents and get approval before you contract, not after.
Lifespan versus cost
Tile typically lasts longer than the underlayment beneath it, meaning future work is an underlayment project rather than a whole-roof purchase. Composition is cheaper up front with a shorter cycle. Both are reasonable; the right answer depends on how long you plan to own the house.