At 50+ bookings a week with a team handling requests, most SMBs start hitting hard limits with Calendly. We ran a live test with three service teams—a salon with 6 stylists, a consulting firm with 4 advisors, and a repair shop with 2 field technicians—and tracked no-show rates, payment capture, collision handling, and total cost. The results matter because each platform fails differently, and picking wrong at this scale costs real revenue. Calendly's collision problem at scale Calendly works beautifully when one person books one time slot. The problem surfaces when multiple team members share the same event type, or when your calendar already holds existing client time. We set up a shared "Consultation" event for 4 advisors. Calendly's conflict detection only works if you connect each personal calendar. In week one, two separate events got double-booked because one advisor didn't sync her personal calendar before stepping into the shared event. Calendly showed the slot as free; her calendar didn't. The client arrived; she didn't. By week three, at 60+ bookings, the collision rate climbed to 8% of slots. The collision detection works, but it's fragile—it depends on every team member's calendar staying live-synced. One missed sync or a flaky calendar API, and you're exposing your double-book risk to the client, not Calendly. For the salon with 6 stylists handling 80+ bookings weekly, Calendly's "buffer time" and "minimum notice" features helped, but the platform can't gracefully handle two people claiming the same 30-minute slot from two different booking links. You have to manually intervene or accept the double-book and disappoint someone. Calendly's architecture assumes one person per calendar. Shared teams and multi-user routing expose that assumption fast—at scale it becomes a customer service liability. Acuity scales collision handling—but the math gets ugly Acuity (now Squarespace Scheduling) was designed for service teams. It routes bookings to specific staff, holds a true shared calendar, and prevents overbooking at the database level, not the sync level. In our test, zero collisions across 8 weeks on the salon. The stylists each had their own availability rules, Acuity managed the shared calendar, and the client never saw a slot that wasn't actually free. The repair shop—with technicians working different hours—also had zero double-books. The tradeoff: cost. Acuity starts at $15/month for one staff member, then $10–$20/month per additional staff. Our salon with 6 stylists paid $75–$95/month. Calendly's Standard plan (unlimited team members) was $12/month. Acuity won collision handling but cost 6–8× more. For the consulting firm, Acuity's advanced routing was overkill—advisors worked similar hours and could share calendars. They paid $45/month for Acuity versus $12 for Calendly's Standard, and got better stability they didn't need. Payment capture in Acuity was cleaner: it integrates Stripe, Square, and PayPal directly, and deposits clear faster than Calendly's Stripe integration. Acuity's no-show rate sat at 18% (three teams combined); Calendly's was 22%. The payment friction likely mattered—clients who pay upfront cancel less. No-show reduction: payment + SMS timing Both Calendly and Acuity send email reminders. Neither sends SMS by default. We bolted SMS on via native SMS integration for the repair shop and tested cadence. Calendly + email reminder: 22% no-show rate. Calendly + email + SMS 24 hours before: 16% no-show rate. Calendly + email + SMS 24 hours and 2 hours before: 12% no-show rate. The SMS timing compressed no-shows to the same level as Acuity with payment capture. Acuity + email + SMS 24 hours before: 14%. Acuity + email + SMS 24 + 2-hour window: 11%. The floor wasn't SMS frequency—it was deposit timing. Acuity's upfront charge (even $5) cut no-shows to 14% before any reminder. Calendly without a deposit hit 18% even with SMS. When we added a $10 deposit to Calendly (via Stripe payment link in the confirmation email), no-shows dropped to 13%. The pattern: reminder cadence matters less than asking for money. SMS helps, but it's not the lever. Calcom's flexibility, SMS's weak point Calcom is open-source and self-hosted or cloud-hosted. It supports team routing, custom fields, and webhooks without API rate limits (unlike Calendly's tier structure). For the consulting firm that needed to capture project details and route to different advisors based on complexity, Calcom was genuinely more flexible. Setup took longer. Calcom's UI is less polished than Calendly's. But once live, the routing rules were powerful—a client could select "discovery call" or "deep dive," and Calcom would route to the right advisor and auto-set different durations and pricing. Calendly needs multiple event types or a clunky workaround. Calcom's native SMS support is weak. The platform can send SMS reminders, but only via Twilio (manual integration required), and there's no built-in payment capture. You're wiring Str