What a small church is actually scheduling
A congregation of 150 on a two service Sunday is filling something like sixteen positions: two adults in the nursery per room, a preschool teacher and a helper, three or four greeters and an usher team, one person on sound, one on slides, and a communion setup crew once a month. None of those slots is complicated on its own. What makes them hard is that they repeat every seven days forever, and that the people filling them now expect to serve once a month rather than every week.
That is a rotation problem, not a records problem. The rota needs depth per slot, a visible bench, a swap route that does not run through the coordinator, and a rule about how late a volunteer can drop. A church platform can hold all of that, but you reach it through a larger structure of people, teams and plans. PewRoster starts at the slot list because for a church this size the slot list is the whole job.
Where the broader platform earns its keep
There is a real point where one system beats several. If the same volunteer appears in your giving records, your directory, your check in station and your Sunday team list, keeping four copies of that person up to date becomes its own weekly chore. A church platform solves that by holding one record everyone works from, and a growing congregation with staff usually crosses that line eventually.
The honest test is who maintains it. A platform rewards a church that has someone whose job includes tending the system: cleaning duplicate records, keeping team structures current, training new leaders. A church where the administrator works twenty hours a week and the coordinator is a volunteer tends to use one part of that platform well and let the rest drift. If that describes your office, a narrower tool you fully use will beat a broad one you partly use.
Moving a rota across without losing a Sunday
Whichever way you go, do not switch in the middle of a published cycle. Finish the Sundays your volunteers already have on their calendars, then build the next six weeks in the new tool while the old schedule is still visible. Two overlapping views for a fortnight is cheap insurance against a room with no adult in it.
Bring three things over and leave the rest: the list of positions with the number of people each one needs, the volunteer list with screening dates and the frequency each person agreed to serve, and the blackout dates people have already given you. Old attendance history is rarely worth the import time. What you want on day one is a correct slot list, because everything downstream, including who the tool tells you is missing, is built on it.