Stubby

for over 40 years i've experimented with a variety of sheet atachments....
in the end a properly tied, snug bowline beats them all for different reasons...
they don't hurt crew and gear like hard shackles, there is no magic to tying a bowline...
it'll loosen up after having tremendous loads on it for long periods....i could go on....
i have 2 sets of sheets pre rigged on my j-30...one set for the blade that can also be used quickly for barber hauling a #1 or #2...
and the #1/#2 sheets which can be put to use in a variety of other ways if need be....
 
i've sailed with some damn good sailors and sail makers and they still prefer the good ol' bowline when the goin' gets tough....
 
but that's just me...
 
some of those other soft systems may be great for sport boats with just one up wind sail...
it's not like you're going to be changing head sails half way up a beat or changing sails during the downwind leg....
and those things happen on big boats....

And on a big boat you want to be able to change things out as quickly as possible, which is why j-locks and soft shackles are being tossed around. A bowline may be nice and secure but it can also snag in the rig and while yes you can always untie one, it's significantly more work than the quick squeeze required by a j-lock and the less time you can spend dicking around forward during a sail change the better.

I have found that bowlines slowly weaken the core, I have had them just let go at the start of the knot in not all that much pressure, a spliced line with a soft shackle or a equiplite wont do that because your not constantly bending and rebending the line.

Personally, I hate T clew rings, they are a royal pain in the arse for inline changes while offshore.  I hate metal shackles because of what they do to the boat and mast, we have so many dings in our cabin top because the previous owners used J clips.

My personal favourites would have to be the equiplites, very quick and easy.  Second to the equiplites I would go for soft shackles, they wont damage the boat as all and they are very easy.  If it ever comes to getting rid of it in an emergency it doesn't take much for a knife to go through it under load either.