Welcome back to the water Robi.

A few tips,

Stitch of tie a long spinnaker cloth ribbon to the very top of your leech, about 1/2' or 4/5' inch wide and 1.5 foot long. This will really help you in trimming the twist of the sail just right. It is relatively easy to oversheet the squaretop. When that happens the boat will move forward with what appears normal speed, HOWEVER, if you would slack the sheet just a little and have the top twist of by some 100 to 200 mm (4 to 8 inches) extra than you'll find that the boat feels lesd bound up and speeds up. Funny thing is that you will feel underpowered as the boat heels less and you may even have to send your crew down to the leeward side BUT the boat speed is definately higher. The ride become smoother and more agile as well. A hooking top (no twist or even pulling the head to luff) is very draggy because of detached flow around the top and a very big top vortex that tries to equalize the overpressure on the windward side with the underpressure on the leeward side of your sail.

With the right trim you boat should accellerate noticeably in the guts. We all have to find this magic trim on our own boats and the only comments I can give anybody is to look it. It is there, you just have to find the trim that does it on your boat with your sail/mast combo. Currently I'm only halveway, I can feel that there is more there but I haven't found the sweet spot myself yet. A fellow Taipan F16 sailor overhere did just find it this past weekend and came 2nd in his local club race.

Also if you are sailing with a spinnaker up you really want to bring your mainsail traveller in alot more than you have in the pictures. Both for speed and keeping your mast straight/on the boat. In most conditions the traveller car never goed further out under spi than 10 to 15 inches (250- 400 mm). Keep the mainsheet firm.