What I like best about APIMAN, it's ease of use for even novice users to get up & running with their APIs in minutes! It was also easy enough that we could have our developers set things straight right away without any assistance from us (which would be great).
The UI looks very dated now - but still functional as ever so don't let this put you off if your looking at using something else which will look better later down stream or when they've updated/redesigned them again! We were able to quickly create new endpoints within existing OAUTH2 providers such Microsoft Azure AD etc., allowing me access into my account data via these services rather than having all those credentials stored somewhere outside where i can forget what someones password / username are!! This allows quicker inputting by other team members who may not know how many accounts.