With regard to staff travel I am still very junior and I have found it works very well. You get one Club ticket for you and family after 6 months with the company but clearly you have to pick your flights sensibly.
Trying to get on the 1 Orlando flight a day in the middle of August is not likely to succeed but trying to get on one of the 20 flights a day to New York or Newark is much more likely.
If you are using it for your family holiday in the summer it is a last minute task. Find the open flights or destinations then book the accomodation. DON'T book your accomodation in January and then expect to get on your flight of choice during the summer holidays. For me it has been very successful but my wife is very flexible and doesn't get too stressed with last minute changes.
If your partner is high maintenance and needs everything confirmed 6 months in advance then staff travel is not for you.
The other option we have is buying confirmed tickets at a discount. Sometimes the discount is fairly considerable but sometimes its only a few pounds. Its always worth checking against the main BA website.