Ian – the Ironwire Lawson carries is very similar to the Dynaglide that many hammockers use. In terms of difference the Ironwire is rated to 1000lbs and I believe that the 7/64 is rated to just over 1500lbs. 7/64 Amsteel will be a little thicker than the iron wire and IMO the coating on the Ironwire is a little slicker. As for using one or the other both can be used for making whoopies, soft shackles, loops, ridgelines, etc….
I think that the amsteel is a little easier to work with but YMMV. Hope that helps