I have the same rig as yours and I have tried both the slide jacks and JT strong stabilizers. There is no comparison.
I tried the slide jacks under my largest slide one season. I had them under the slide for 3 months while snowbirding in Az.They did reduce the movement in the trailer a lot. However even though I readjusted them a couple of times, they warped the leading edge of my slide floor. So when I brought the slide in the inner/leading edge of the slide floor was sticking up over an inch above the main trailer floor. It has subsequently settled back down to about 1/2 inch since I haven't used the jacks in 2 years.
I installed the JT strong stabilizers 2 years ago and they are great. They make the rig more stable than the slide jacks did and they are eazy to use andthey don't take up any space to store them. There are some cheaper JTknock offs out there and they look to be made just as well. I would have got one of them if I had known about them at the time. I also use BAL wheel chocks, but with the JT'S, I don't think they add much to the stability. They just keep the wheels from rolling away.