I use this since it has a very large base that makes it stable. It also has an integrated jack stand for safety.
The other thing that surprised me was that when I went to a major tire store in Texas(discount tire) for new tires they wanted to use a floor jack on the end of the trailers frame. The manual that came with my Starcraft and Keystone state specifically to Jack only at the frame adjacent to where the springs are attached. The tire place made me show them the manual.
After they were convinced of the proper location, it turned out that their jacks would not lift the trailer off the ground enough to get the tire off. I had to get my jack out to lift the trailer. I thought this must have been a fluke.
The second time I had this problem was with a 30' Keystone hideout. The tire shop wanted to Jack it up at the axle. Again I had to be very direct and actually raise my voice to stop them from jacking it up on the axle. Their rationale was that they "do this all the time" Again I had to use my jack.
Make sure and watch how those guys handle your rig!