What is Moodle?
Why Moodle is Best?
Why Moodle Matters.
Moodle is Important to VET Students
These links explain a little about Moodle, but very little. I don't think they are precisely what you want, but they do provide some insight into the ways in which Moodle is used, how it is seen. There are a lot of links like these, but these were the first few I found.
The most interesting one is "Why Moodle Matters". Basically, the author is suggesting that the numbers of users are actually self-reported, and Moodle's user base is open to anyone who wants to look at it, and they are just the registered users. Unregistered users don't get counted, and I know three who are not registered, mainly because I never bothered. (They are all small, limited use anyway, and when I have raised it, the owners have all said, basically "Erm..um...oh..." which is code for "I don't want to upset you by refusing.") I wonder how many other micro-Moodles there are that are not registered.
The main points about Moodle:
Unlike Blackboard, you don't have to wait years for expensive updates, you can upgrade every year if you want for your costs, little more than wages, and no licensing fees.
Moodle does not pretend to be anything other than a LMS, it is not a mix of LMS and SMS.
The main benefit of using Moodle is right here, these forums. No other product, AFAIK, has such a vocal and enthusiastic support network. Have a problem? Just ask, someone will help.