I currently have my turning block and cleat on the side deck at about the shroud level, just below the deck height. It has the disadvantage of making the jib sheet go through a number of ugly tight turns. Come to think of it, these ugly tight turns out to, and from, the tankside put quite a load on the jib fairlead in/out control. I think that the only real advantage is that the jib sheets cannot get fouled with the spinaker sheets.
On my other boat, Men in Black, the jib sheeting is at the thwart. This lets the helm adjust the sheet when necessary, and allows the crew to sheet the jib with the rearward hand, which is good for crew stability in heavy air (pulling from the front and going down a steep wave at the same time is deadly). As for the tacking technique, I always tack facing the front of the boat, and have never had a problem. This might be because my sheets are continuous, or because I use the "trailing hand" technique. It goes as follows for a port to starboard tack:
1) Before the tack, unclip from trapeze wire, hold onto handle with left
hand, and don't uncleat the jib;
2) Once the boat is near head-to-wind, swing into the boat and reach for cleated jib sheet at the starboard cleat with the right hand;
3) At the same time, grab the jib sheet on the port side near the cleat with the trailing left hand;
4) When the jib starts, or is about to start, backing, uncleat the starboard side and then grab the starboard trapeze handle with the right hand;
5) Throw yourself out the starboard side, pivoting counterclockwise to face upwards. If the jib sheet was grabbed near the port cleat, almost no pulling in will be required becase it has already been pulled in from the cleat on the port side to the hip level of the crew, almost seven feet. At this point, the frontward right hand is on the trapeze handle, and the rearward left hand is on the jib sheet. This is a very stable position for the crew.
6) Once the jib is sheeted and cleated, hook onto the trapeze wire.
7) Repeat steps 1 through 6 as necessary.
At the Weymouth Worlds, I noticed that many of the newer boats were using thwart sheeting, and I'm considering going back to it.