OK, I'll add my two cents to this mess...

All the Tboats I have seen recetly (US Nationals two months ago) are using curved jib tracks with simple limiters/stoppers on the track. Here's a couple of links to how my boat came:

Jib1
Jib Track

I have since replaced the loops of line through the holes in the track with quick-releasing pip-pins so that we can easily change the car travel range while racing. I am thinking about changing this to a single line running fromt he center of the track to the car, which will allow even easier, fine adjustment. Bill's point that such a line MUST be adjusted at the mast, requiring crew to come off the wire is solved by running a (doubled) control line to the beam ends, just like every other major control line on the boat. I have seen one other setup on a Tboat, where the jib car was placed along the track by a windward & separate leeward control line, kinda like some old style main traveller setups. This requires uncleating, re-positioning with each tack...and therefore you lose the self-tacking advantage.

Re. Jake's comments on full-battened jibs...I have transitioned from a "soft" jib to the full battened Tboat jib. I find the new setup less responsive in light air. Also, you lose the ability to run a furler...not an issue on class legal Tornados, but the F18 crowd will likely not embrace this...

Mike.