Damn, I've not sailed any of those....

Oh, well; I'll just compare my F16 experence with my Inter 17.

Main differences off the water

1, The Inter 17 is longer (10 inches) and carrys a fair few more KG around. My boat had an Alu mast and so was a lot more than an I17R or a F17. I think an F17 is 134 or 140kg, alu was probably more like 150-60.
2, The F16 IS much lighter, my boat should be close to minimum weight and so around 104kg single handed - this does make a massive difference when dragging it around the boat park even with proper Cat trax.

On the water.

1, As soon as the I17 is floating, most of the weight issues disappear. It is a dream to sail and the my boat had amazing balance, don't know how, but I could let go of the tiller upwind and down (with kite up) and the boat would just track along.
2, The F16 I have (Stealth) has very flat bottom hulls, this makes it very skittish on the water. But it does appear to rise up and plane in certain situations.

upwind.

1, The I17 was a more "grunty" boat, Bigger and heavier and so the sails are lifting more weight, thus sheet loads are heavier, but it's still no problem sailing for 15 miles on one tack with the kite up. I had a 19sqm kite and it was hard work, but not impossible.
2, The F16 requires more Finesse when tacking and gybing, it is a lot quicker around the turns (sure the flat bottoms help here). And I've found myself "over rotating" when wire to wire tacking at times (still).
3, Speed of the two boats is comparable upwind, I the light stuff, the F16 stomps all over the I17, The F16 wires earlier and then really makes a difference. In the moderate stuff (10-20) the boats are similar upwind, and then when it gets windy, the I17 starts to gain a little.


Downwind

1, Downwind the I17 was fun, the F16 is a scream. F16 Spi is 17.5sqm, I17 19 as I said. F16 also has a bigger mainsail (than my I17, I believe the F17 has a comperable mainsail size). The F16 just picks up and flies in lighter winds when the 17 would still be in non hull fly mode.

2, F16 Sheet loads are lower in the light stuff, and then similar in more wind. The F16 is MUCH quicker down wind.

3, Both boats are quicker when wiring down wind, the F16 goes into this mode more quickly simply as it is lighter


general stuff

1, People say that proper F classes turn into arms races, now this is partly true, but the evolutions on the Inter 17 have come thick and fast and so you cannot (IMO) us this argument when comparing the Inter 17 against the F16. Yes, F boats do evolve, and it can be seen in the F16 class at present. We are all thinking hard about our boats and how we sail them. In the 6 years I had my Inter 17, we went from the Inter 17 with the Alu mast, to the I17R with a carbon mast and I believe a lighter platform weight, and then to the F17 which had a lighter platform weight again.

2, The weight of the Inter 17 IS an issue on the beach. It is NOT an issue on the water.

3, The more open rules in the F16 allow you to tailor the boat layout to what YOU want, the Inter 17 rules do not.

4, Cost for cost, the F17 was MORE expensive in the UK than my Carbon beamed Stealth and you get more sails (but less hull length) as the boat can be sailed one or 2 up.



overall

I would say that on the water, the F16 is more fun as it is just faster around the course for less effort, lifts a hull earlier and is generally so much fun to sail.

There is also a bigger fleet of F16's in the UK than Inter, F or I17R's.

The F16 can also be sailed 2 up which makes a massive difference to me with kids that are growing up.


Would I buy another Nacra F / I 17, yes, but there would need to be a big fleet to tempt me away from the F16 fleet.