[B_and_D]

We almost replaced ours with those, but they weigh a lot more. The main disadvantage to the older style jacks, for us, has been that in an uneven campsite, you can't always lower them down. We talked about getting an adjustable jack stand to use for the corner (there's usually just one). On the other hand, they (the scissor jacks) can be used when changing a tire, to raise up the TM, from what I've read. We have to use a series of jacks & blocks under the frame.

The old style jacks also getting kind of hard to find, not everyone carries them.