Robin,
Mark is heftier than you are (or should I say were as I haven't seen you in some years ! ? ). I'd commend that you retain the rear toe-loop. If it's blowing hard and gusty and you're on a screaming reach (including the very broad reach you'd sail downwind) and the bow(s) start to go under then having a foot in the rear toe-loop may well prevent you being "slung" forward and help prevent a pitchpole or cartwheel - but having a foot in the toe-loop might not be good news if you do pitchpole and couldn't get you foot out quick enough. There mixed views on this amongst the best Sportsters - you might find some if you use the Search facility on the Chat pages. You're a good sailor, so you will come to your own conclusion after some experience.
On a beat, there is little or no chance of a pitchpole, but as well as wanting your feet in places other than where there are toe-loops you may want to move fore and aft a little as you sail through some wave patterns. I think there is unanimous opinion in favour of removing the forward and middle toe-loops, and applying grippy tape (as class approved at AGM). Having grippy tape all the way aft of the rear beam to the transom can provide valuable extra grip for the foot not in the toeloop. Also, if the wind is strong but without sudden heavy gusts you still have the option of not using the toeloop at all. If it's really strong and gusty, a tip (originally from Kevin Dutch) is to trapeze with the rearmost foot on the transom and the forward foot on the side (or even in or against the rear toe-loop) - you have to adjust the trapeze wire to maximum length.
When I sailed at Cat Club at Sheerness I eventually sailed mostly Sport Mode, because I could usually drive the boat through the waves (mostly a wide against tide short steep chop) much faster than I could sailing Unarig, including on the beat. In different wave/wind conditions, esp inland waters, on the beat there is often little or no advantage for Sport over Unarig (as others point out), and the real benefit comes on the reaches and in stronger wind.
Mark pointed out that sailing Sport Mode involves different technique to Unarig on the beat and downwind (I'd add that 2-up Standard Mode is much like Sport Mode). I remember to talking to Stuart Snell at Carsington a couple or so years ago when I had been sailing Sport Mode : Stuart put it more strongly - he said that Sport Mode and Unarig were really 2 different boats to sail.
But sailing Sport Mode is so much more fun when the wind is enough to get you on the wire.....
