I use Hostbuddy, and it is integrated with my PMP, which is Hostfully. 

This is integrated with Buildium and works well for us.

I am hearing that some are integrating AI to interact with tenants.

While many hosts running 5+ rentals may find that cost justifiable for the increased revenue these tools can help generate, that's often best achieved through a much broader set of integrated tools and outreach. 

I’ve successfully built a stack that automates the intake and skip-tracing process for approximately $0.15–$0.30 per lead (API costs only).The Strategic Flow:Data Integrity: Using Google Address Autocomplete to ensure zero-error data entry from the start.Instant Valuation: Pulling real-time market data to provide the seller with a custom offer range immediately.Automated Skip Tracing: The system automatically pulls legal owner names, mobile numbers, and emails the second the form is submitted.Remote Management: I manage the entire logic (margins, repair costs, SMS triggers) through a Slack/Telegram integration so I don't need a heavy CRM.I’m currently running this through a Google Sheets backend to keep the tech stack lightweight.I’m curious to hear from the veterans here—at what volume does it make sense to move away from 'all-in-one' platforms and into custom API-driven automation?

But, maybe that is just the way this particular lender integrates data...

@John UnderwoodHospitable: $104 a month for 5 properties on the Professional plan (this includes Dynamic Pricing and the smartlock and thermostat integrations to my propertiesNotion: FreeBlink: $10 a monthNoiseAware: $30 a month (I only have this on 2 properties currently)Schlage and Ecobee have no recurring monthly costs, just the upfront device costSimplisafe: $10 a monthQuo: $15 a monthGoogle Workspace: $10 a monthQuickbooks Plus: $120 a monthTotal: $300 a month for 5 propertiesI'll be honest, I'm not sure the exact % of net annual income.

It also integrates with most of the software you use to manage your business. 

Ideally something that:Covers damage, liability (eg. stained linens, broken TVs, etc.)Integrates easily (API or simple per-reservation purchase)Reasonably priced per bookingOption for Guest Screening (ID Verification)Anyone using Safely, Truvi, Proper Insurance with per-booking options, or something else?

Beyond maintenance a good PM software will auto assign late fees, e sign leases, have integrated applications and leasing and much more!