I have the industrial-strengh version of #2.
Moving a car like, oh, a '85 XJS

isn't exactly a piece of cake when it's on the dollies, at last if your floor's not perfectly flat. Moving the RX-7 is a lot easier...
Having a flat *and SMOOTH* floor makes a big difference. You're not gonna go over any bumps, so unless the floor is pretty good, just forget it.
Leaving the whole "move it? it's still a very heavy object" thing aside (and I can give tips on how to move cars on the dollies, tips that involve hammers and/or steel toed work boots), IMO the second one is probably the way to go. So many people are kinda

about jacking cars up and you don't want an "oops". The self-jacking nature is a simple concept to put into action.
But it takes a bit of muscle just to pump the lever to work those dollies. Not really tough IMO, but again, I'm not in my 60s. I like mine, use 'em to shove the [insert currently neglected car here] into the far corner of my shop where I can admire it as an interesting mechanical device instead of pretending it's actually transportation
