Oh, and another big issue that is worthy of mention for each airline : soft or hard landing.

If you don't step on a flight after qualifying for WP, QF give you a status soft landing (assuming they don't comp. you the status, which they sometimes do !), dropping you one level a year - so from earning WP it will be at least 3 years before you are a bronze again, with a year as Gold and then one as Silver in between.

Other OW carriers (AA ? Little idea personally about others !) I understand will drop you straight from top-tier to bottom-tier.

Very useful info for e.g. for a person who may have one big flying year but know that in subsequent years they won't be flying much, and wants to maximise status from this big year and wants to pick the right prog. to join accordingly.