I find the TAF3 worse than the TTF. I wish Oz would keep it simple and just put 2 hours validity on METAR and ATIS like they do in SE Asia. Why confuse things, especially for international crew? I remember a course in Singapore for new training Captains and someone started talking about TTFs. Non Australians were ‘what the hell is she talking about?’. Now we have TAF 3s. Why?
TTF was a METAR with trend forecast attached allowing its use for planning up to 3 hours from observation. A METAR is simply what in most cases the automated sensor saw exactly up above it, meaning its significance in isolation means nothing for what will happen in the next 30 minutes let alone 2 hours. All you use a METAR for is to confirm that the TAF is running true, or not.
There is one little part of commercial operations that some are forgetting here. The PIC of a commercial charter or RPT operation must be familiar with the local weather patterns and conditions for all ports they operate to. It is not sufficient to say the forecast was wrong continually. Forecasts are educated witchcraft at the best of times and rely on reports from pilots, observers, radar, sattellite imagery and automated stations for accuracy and updating. I really haven't seen much change to forecast accuracy in many years, it's neither better or worse, however the tools for self judgement on the weather and questioning are all still there. When you know the patterns you can see errors, you can ring the MET office and talk with an officer and get their opinion, the forecast may change as a result. I've changed a few TAFs just by being proactive and knowing the local patterns and talking it through with the met office.