What to note before the visit
Record whether the head is cracked, buried, tilted or failing to rise. Note nearby mowing damage and whether neighboring heads perform normally. A photograph taken during the affected zone's cycle can explain the pattern without dismantling the head.
Replacement choices
Ask whether the proposed body and nozzle match the application and the other heads on that zone. A taller head may address plant growth; it will not solve a supply-pressure problem. Replacing every head is a different scope from repairing one damaged component.
What the quote should cover
Clarify digging, fittings, nozzle selection, adjustment and cleanup. Ask for an operating check that includes adjacent heads, not just proof that water exits the replacement.
Useful question
If the same head has failed before, what will prevent another impact, burial or pressure-related failure?