That's a pretty great overview. I've learned SystemTap myself because that's what's easy to get going in my environment. I was very surprised once I "got" it. It can do pretty much anything you'd ever need. I haven't needed to look at anything else yet, although I've been meaning to play with the LTTNG tools, as I like the idea of setting up the experiment just once, recording everything, then investigating afterwards. This [1] is a good walkthrough of that workflow.
[1] http://lttng.org/blog/2015/02/04/web-request-latency-root-ca...