J,
I got into Steadicam for similar reasons as you are quoting. I needed stabilisation for projects I was shooting. Within a few months, I had ditched the projects to concentrate full time on Steadicam. In my limited experience, Steadicam is too big a thing to just 'add' to your repertoire. (Have you read 'The Road Not Taken,' by Robert Frost?)
I don't have a JR, so can't tell you anything other than that I saw Garrett Brown (the inventor of Steadicam) using one to magnificent effect. A JR is something you can pull out of the back of your car and use when you need it. That it is small, inexpensive, and has limited application seem, in your case, to be points in its favour. Hopefully, someone will chip in with XL1/JR experience.
Chris