The only experience I have with lifts, other than the kind you find in gas station garages (big single cylinder), is with this one that my brother has:
That two post you linked to looks scary to me, personally. Not having the posts tied together some way does not look all that safe. I would recommend you bolt it to the ground when using it.
The four poster my brother has works well, even though it isn't bolted down. He had plans on moving it, but it's pretty much stayed put where it was assembled. He's had a Suburban up on it so it is robust.