I think the confusion here is this:
In my opinion, if you're going to use the Hi-Lift as a recovery device you should be carrying both chain AND straps. That being said, NEVER use the chain for pulling a vehicle with another vehicle, and NEVER use the strap to pull with the Hi-Lift.
If you're going to use the Hi-Lift as a come-a-long (which I've seen done, it works well) always use chain because the chain does not give, which will give you the max out of every pump of the handle. A strap on the other hand would stretch, which helps it store energy for pulling, but this benefit is never realized unless the vehicle actually starts to move a little. There's nothing to worry about when using a chain with Hi-Lift, because there's no violent jerking going on, just steady application of pulling force. I would get three heavy (at least 20K lb work load) chains of varying lengths, say 5' 10' and 15'. That plus the length of the Hi-Lift (almost 5 feet) will give you plenty of options whether you're pulling near or far. Also, if you're going to pull with chain make sure you get some heavy duty D-clevises as well plus a short tree saver strap with heavy loops on the end so you don't scar the trunk of the tree as you pull.
Straps on the other hand are the best thing for pulling a vehicle with another vehicle. When you pull and the nylon stretches you're actually multiplying the pulling force of your vehicle. Once the vehicle you're pulling starts to move a little that force is released. I think that what _nascar_ is saying is just that-straps are good for pulling with another truck, but not a Hi-Lift.