All preventable once communication has lanes.The hardest part todayTraining tenants on how to communicate, not just responding faster.

Here's the breakdown of my basic observations after ~2 weeks on each solution: Guesty Lite: - $39/listing/month (unclear if this includes standard 1% commission)- Superior iOS app (faster, locally cached, better organized)- Cleaner guest portal- Targeted to smaller portfolios (1-3) vs Pro (4+) - Clean HUD/dashboard for checkins/reservations- Excellent message automation that links automations in a templated flowchart design (best I've seen)- Awful analytics, similar to GfH (upsell to Guesty Pro)- Dynamic pricing, damage protection, lock management, liability, and outsourced communications (unique) all relatively expensive (aligning to Guesty's overall penchant for chasing ever-expanding upsells)Hospitable:- More third party integrations- Comprehensive analytics- Customizable dashboards are nice - Useful in-app/site help tours- iOS app is effectively a responsible website (slow, uncached, voids iOS design rules)- Messaging rule management can feel cluttered (dozen-plus rules to start?)

It also has a bunch of really unique benefits/tools for your rental portfolio (Lease Indication Tool, Expense Tracking, Maintenance Requests, Rent Collection, Tenant Communication, etc.) in one central place.

It ensures all your calendars from all your listing platforms are synced to avoid double bookings, manages all communication in 1 spot, plus more.

If I have online version, how many users/pc/devices I can get?

The trick will be the expense of installing and maintaining the devices. 

In the leasing contract it clearly states that the tenant is not allowed to change any security device or locks without written permission from the landlord.

Tenants bring lamps and all sorts of electrical devices into the unit.

VRBO and Airbnb have all the basic communications that I use.

COMMUNICATION.