Not sure about Bah-in, but Legend I like right away and during the first two weeks of steeping personally. Many insist to their taste it is best after 2, 3, or even 4 full weeks. With NET (naturally extracted tobaccos) more than any other
juice in my opinion, steeping alters the flavor significantly, often for the better, but again for ME, with Legend I now like to NOT take the caps off and allow it to steep slower since MY preference is the fresher flavor of the
juice. Others from HHV, like Serendipity and Dragonsfire, I prefer after two to three weeks of steeping, the first two days with the caps OFF.
You really will have to figure out at what point your preference lies by sampling fresh, after a few days, after a few weeks, etc. Take notes if you need to so that if you reorder a particular juice, you have an idea of when it is best, to YOU.
Lots of opinions and recommendations on the HHV sub-forum here:
The HHV Army
And a steeping specific thread within here:
http://www.e-cigarette-forum.com/forum/hhv-army/374706-hhv-juice-steeping-information.html