A chain fails, those links are like shrapnel. Plus, a chain is harder on the vehicle, as it has no give to it. A strap will stretch a bit to absorb some of the shock as the slack is taken up.
I carry a 30'x3" strap that is rated at 30K lbs.
Always buy a RECOVERY strap, not a tow strap. A tow strap is much lighter duty and has metal hooks at the end.
You want a recovery strap with loops at each end. Some catalogs refer to them as "snatch straps".
And yes, a chain is handy, such as rigging a high lift for winching duty, but I wouldn't use one in place of a strap.
check out
www.recoverygear.com