With reference to Mortgage Mutilator, you don't have to be over 55 to get benefit from putting extra into super, especially when you consider someone in their 40s, super only started at 3% in 1992.
If you do it as a salary sacrifice, you only pay 15c in the dollar tax, rather than 32.5c or 37c tax. Then the earnings in your super get taxed at a lower rate as well. There's a limit of $25,000 a year, including what your employer puts in.
It's a balancing match, so that you don't put too much in and so can still retire early. Also, if you're retiring early you won't be getting that 9% for as long.
Also, some people do get contribution matching in Australia too. For 5% in, I get an extra 3.75%, more if you consider the different taxation rate.
Partner a part time income earner? Add $1,000 to their super, and the government will throw in an extra $500.
Super funds can be a little stodgy performance wise, but if you max your perks putting money in, it makes sense.
Sorry, gone a bit off the main topic here....