The only LMS software I have used is Blackboard. Both in my High school and now in college. I like having one space where I can find all the information I need. It also helps me navigate and get the information I need quickly since I can understand how to work the program.
I feel like using them in the lower grades with the students is more difficult, but can be useful. For instance, if all the students have laptops, I can put a worksheet there for the students to complete rather than wasting paper. Also, I can have a mainstreamed place to post their grades and let the parents have access to them.