As of this writing, there isn't anything I dislike about Kloud's product or service yet! So far as we've used it internally within our organization (about 150 people in total), we have had nothing but positive experiences with their customer support team - who are very responsive by email & phone call when you need help troubleshooting any issues that may arise during implementation / use.
Great all around experience so far. We'll be using them internally to host conference calls for employees