The problem with rvm was always that it tried to do too much. With a tool like that, as long as it's working, you won't see the downside. When it breaks, it breaks in complicated, hard-to-debug ways. If you're saying it's reliable for you, that's great. That wasn't my experience.
Rbenv is much smaller and only does ruby version changes and installations with the ruby install add on. rvm is bigger and has more features but is a bigger pain to use in my experience.
I fell on rvm because it seems to be the "default" recommendation. I don't see a need to use something "better" if the raw tool does the job perfectly.
I do get annoyed that "rvm list known" tends to only show old versions. For example, it suggests it can install ruby-2.2.1, but I'm fully aware 2.2.4 is available, as is ruby 2.3 now. And for me at least, this problem is consistent after applying the standard advice of "get the latest rvm".