I think there are two basic options:
For the person who wants to research rope, learn to tie knots, splice/whip lines and choose their own shackles, they don't need the running rigging calculator. They can research, learn and do. But it does take time.
For the person who has many projects lined up and are spending their time learning and doing other things, that can't be bought from a store, the running rigging calculator is a great way to get new lines that are ready to go.
As to wire/rope or all rope, let your sheaves (and costs) be the guide.
APSLTD may offer options not available from this site's store.
