I finished Black 2 this week and covered my last blind spot with the main series. My opinion on the game is mixed.
Returning to Unova after being away for so long was nice, but I can't imagine being engaged by the single player game only a year after the the original gen 5 releases. Although the "two years later" conceit is interesting on paper, the scenario doesn't go much deeper than "Team Plasma is back!" Some towns have changed to varying degrees, but all in all it feels primarily like an attempt to make one more quick buck with the gen 5 assets. Some instances of dialogue haven't even changed (namely, the E4).
Although most of the story falls flat, I did enjoy the flashback vignettes that familiar faces share with you on your journey. Some of them do little but service the stark narrative of Team Plasma's resurgence but others provide endearing color to the gym leaders and assorted cast. What's more, the gym design is particularly spectacular; it might be the high point of the series in that regard. Each gym expresses its aesthetic to the fullest extent possible through the concerted effort of its music, environment, and puzzle design.
From a value perspective, I'd probably recommend B2W2 over the originals even if the scenario is significantly less interesting. It's essentially the equivalent of gen 2's return to Kanto with 200% more content and half as many meaningful changes from your last visit to the region.
Oh, and your rival is a dope, again.