The largest flaw with jughandles is the matter of what's known as "driver expectation". You have to go to the right to make a left turn. A bit counterintuitive. So advance signage for it is necessary.
They find themselves more useful on divided highways where often the place you're looking to get to is on the other ide of the road and will require a U-turn to access. The jughandles permit U-turns, ordinary protected left turn signals really don't. Certainly not as safely, anyway.
If the highway isn't divided, then it starts to become a bit pointless, although there are cases where geometry will dictate it. For instance, High Ridge Road (CT 137) at the Merritt Parkway (CT 15)
. Traffic from 137 north to 15 south uses a small jughandle to get to the ramp. In this case, the problem is that due to the limited width of the underpass there isn't room to put in a left turn lane. So the state improvises instead. And it's nasty. At rush hour, that jughandle always backs up into the right lane of 137 under the highway, so if you're not looking to get on the parkway you really want to be in the left lane.
Meanwhile, southbound, getting in the left lane will likely get you waiting behind someone looking to make a left onto the parkway north or onto Buxton Farm Road neither of which has a left turn lane, again, due to lack of space.
That overpass was redone in 1994. I remember them redoing it. If CONNDOT was more in touch with the situation, when they replaced it they would have done so with a wider one that permitted a fifth lane underneath for left turns. But alas, they did not. And so here we still have what, as far as I know, is the only jughandle in the state of Connecticut. And a lane in each direction that through traffic will want to avoid.