I had C-Jacks (BAL) on my previous TT and let's just say they worked. My new TT came with Scissor jacks and yes indeed they are cheaply made. I had one fail so rather than make a warranty claim and get another cheap jack I replaced it with one of these from Amazon:
A lot better made than the original with a nice straight screw and better paint than the "rattle can job" applied at the factory.
Half the price (each) than the C-Jacks and for me they work better, especially on uneven sites where I need to use blocking.
As 5-Picker mentioned, they're merely to STABILIZE as people move around inside. Not lift if you haven't properly leveled by adding spacers under wheels as you parked.
A side note: The instructions for stabilizer jacks usually have a caution about using impact wrenches to lower them. I constantly hear people using them but if you look closely to how the hub where the wrench is applied, it's welded to the threaded shaft. Looking at the welds should illustrate why impact wrenches are not recommended. In short "they ain't all that great" and using an impact wrench MAY result in failure of the weld. Now you have a jack you'll need to bungee cord in the UP position on the way home. I find a 3/8" cordless drill to work just fine,