Pity we have to read through all the bickering to find some useful info.

I have a question for the guys who have tried and experimented with these setups, based on the idea that, if I`m gonna ever put a self-tacking jib on my boat, I`d like to use the straight track for a few reasons. Some of these being lower cost, simplicity, and the fact that, if there`s anything on a boat that sticks out the way a curved track does on the Tiger and Tornado`s I`ve seen, it`s sure to kill my crewmember in a big capsize.
I never even considered all the finer points discussed on some of the posts above, just thought "bolt it on & go !"

So, I now understand (some of) the drawbacks of a straight track. From what I can gather the biggest hurdle is that as the wind pushes the jib out, the distance between the clew & the sheeting position grows, and the sheeting angle changes, so the leech closes. I`m not sure I understand why the sail wants to centre back in to the middle, surely the pressure in the sail will keep it out to the point where it is set ? I would have thought that having a stopper on the track would prevent the leech closing off, the traveller car hits the stopper, and the amount of sheet tension would then determine the leech tension. Maybe you`d need two control lines to acchieve this, but it would still function as a self-tacker, both upwind and downwind, the only downside is that you might need to move the stoppers out a bit for downwind sailing. With a spinnaker this might not even be a big issue.
Bill`s solution goes over my head, so if anyone can explain why the 4:1 purchase and batten are necessary, I`d appreciate it. The Mattia F18 & F16 don`t appear to have any of these items and are fitted with a straight track, has anyone seen this system or sailed with it ? (Attached pic.)