Open Educational Resources (OER) could be used by educators and learners for online teaching and learning. All over the world, various OER repositories and directories curate OER in various subjects. However, little is known about their quality, popularity and usage. This paper investigates and analyses qualitatively and quantitatively 13 well-known repositories of OER (ROER) from the users' point of view. The following web traffic analytics tools were used: Google MobileFriendly, Google PageSpeed Insights, OpenLink Profiler, SimilarWeb, and WAVE. Most of these ROER curate OER and links pointing to OER of multiple types, multiple languages, multiple disciplines (subjects), and multiple educational levels. Also, almost all of them provide mobile friendly design, some form of OER quality evaluation, and facilities so that anyone can search them for OER and their members can interact, communicate, and collaborate among themselves. However, most of them provide poor speed and their information about their OER does not always correspond to the reality. Most of these ROER have registered members and social media followers, and are well recognised by thousands of websites that point to them. Thousands of users visit these ROER. On average, visitors visit 3.6 pages and spend 2.6 minutes per visit in an ROER.