My husbands been driving me nuts to get the wedge since he thinks he is getting to old to be lifting tubs!
Our friends have one and they said it has been a great asset.
We have the spa jack and it has been great. The 1 disadvantage is the plate tends to slide off easy and the arm slides out of the wheel so when you go to pick it up you leave the whells behind, becomes a pain. Maybe they have changed that since we purchased ours.
In addtion to the castors, we use plastic strips to move tubs around. if you cut an old truck bed liner, the kind that just plop into the trucks, into strips the spas slide great on them doing no damage to the surface below the spa. I know, its a bit Hillbilly, but it works great!
With these tools, it takes just my husband and I to deliver most the tubs.