You have to host your IDX/RETS on "Displets" servers. Do a test and you see how slow the pages load, even with a fast internet connection. On mobile it does not load at all sometimes. Data from wrong regions show up in "your" area. No way to delete "powered by displet" advertisement. Can not use a standard Google sitemap plugin for your listings. You have no control over your data or content at all.
It is also not cheap.