I do not have feedback on them, but have looked at other platforms before and it was prohibitively expensive.  If you use the major platforms and/or collect deposits you should be fine.  In over 30k reservations over 10 years I have only once had guest damage exceed $2,000 and it was about $8,000 for a fire resulting from fireworks on the 4th of July last year.  If I paid $10 per reservation (what another company offering a similar product wanted) I would have spent over $300,000 to date.