While an uneven season, with a mix of very good and more episodes, some average ones and plenty in between, not every change settling straightaway and a couple of other things that didn't come off well (especially the exit of Southerlyn), Season 15 also could have been a lot worse. Due to having the worry as to whether the lack of Briscoe would hurt it, luckily that didn't hurt the season too awfully but his absense was deeply felt for the rest of the show's run.
The sixteenth episode "The Sixth Man" is one of the mostly very good episodes, with many great things. It is a case of one half being stronger than the other (which was not unheard of throughout 'Law and Order's' run, actually it was quite common in the early and latter seasons) and really hated one of the crucial characters which did unbalance the episode a bit. But again as said, there is a lot to like here and Borgia has already proven that Southerlyn is not missed at all.
Beginning with the not so good, it did start off a little routinely. Loved the detective work and Fontana and Green have come on a lot as a partnership, as has Fontana as a character, but the first quarter doesn't have much new.
Also thought that "The Sixth Man" overdid it with trying to make the accused as unbearably obnoxious as possible, even for somebody you are supposed to dislike. It is true absolutely that people behave badly when struggling with fame and such (and a vast majority do), but all the accused's character flaws are exaggerated to the point of being an annoying and positive character traits-free cartoon.
Having said all of this, a lot is great. Production values are slick and professional, not ever resorting to cheap or untested gimmicks or anything. The music is haunting in the right places and isn't constant or too loud, and the direction gives the drama urgency and breathing space.
It's a thoughtfully scripted episode and the legal portion is riveting and not too complicated. The acting is very good all round, Sam Waterston particularly, and Annie Parrisse in only her third episode as Borgia is already a vast improvement over Elisabeth Rohm.
Overall, very good. 8/10.