The engagement and the wedding day are two different products
A planning suite is organized around the engagement. Design boards, guest lists, budget lines, client checklists, and a portal the couple logs into all assume a relationship that runs a year or more. That is real work and a real product, and if you sell full planning it probably deserves to be the center of your stack.
A run of show is organized around eight to fourteen hours. It is made of call times, load in doors, cue lines, and a room flip. The people reading it are not your clients. They are a florist on a ladder at ten in the morning, a catering captain counting covers before doors, and a DJ who needs to know the toast order changed. AisleTimeline is built for that second document and that second audience.
What an automatic change notice is actually worth
Think about the last time a ceremony start moved by half an hour. You edit the master timeline, export a fresh PDF, write an email explaining what changed, attach the file, and send it to eleven vendors. Then you answer four replies asking whether their own call time moved. That is most of an evening, and on a busy wedding it happens more than once.
AisleTimeline changes the time in one place. Each vendor opens a view showing only their blocks, and the ones whose times shifted get told without you writing anything. You are not really comparing feature lists here, you are comparing an evening. A broader suite may be able to approximate some of this depending on how you have set it up, which is worth testing on an actual wedding before you decide.
Running both without duplicating work
Plenty of coordinators keep a planning suite for the engagement and move to AisleTimeline for the final three weeks. The handoff point is easy to name: the moment the timeline stops being a draft the couple is reviewing and becomes a document vendors will act on. Everything earlier stays where your clients already look for it.
If you do run both, pick one home for the master times and never edit the other. The failure mode is not the software. It is two versions of the same Saturday, one of which a catering captain printed on Thursday and taped inside a kitchen door.