I usually redeem F on SQ. The F product for SIN-SYD is supposed to be great. Unfortunately I am flying in J for SIN-SYD and only have experience with the older suites product. If it was me and you can find availability I would consider flying the new F product on the SIN-SYD route. You get more time with AKL-SIN but its the older product. I have done shorter inter regional flights on SQ in J, but have never flown J with them on an ultra longhaul the same way I have done in F. On an upcoming trip I am doing EWR-SIN-SYD all in J and then SIN-FRA-JFK coming back in suites, so give me a month and I am sure I will know all I need to know about long haul J flights with SQ. The bottom line is it depends on the person but I always found F to be worth the extra points IF you can find availability AND you don't mind spending the extra miles. From reading the reviews I get that sense that some other airlines have a better hard product when it comes to J flights, but its hard to imagine that it would not be a massive step up from what you get in the US which is usually crap.