Though I haven't quite understood the title (I know what a Venn diagram is, just not what it's got to do with the story), I enjoyed this story more than I expected. I mean, it was advertised as "Nightwing vs. Deathstroke" and though sometimes the X vs. Y things can be fun, they aren't the kind of set-up for a story I find interesting. Also, I only have the vaguest idea of Nightwing's past history with Deathstroke, so I'm missing much of the background information from the (as I understand it) Titans that makes their relationship and conflict interesting.
There are enough hints at their past that I didn't feel completely lost even without knowing particulars, and I found it interesting how Nightwing reacts to Deathstroke and his business as an assassin, as well as that Nightwing decides to solve their conflict by just paying Slade a dollar more than the original client paid for the contract on Amy. Obviously for Slade only the principle and adherence to his own code matters not the money itself, because he didn't even manage to take the money before he had to flee from the police, but it's still implied that he won't make any further attempts to kill Amy. Anyway, I like Deathstroke, and I hope I'll get to read the Titans issues about his history with Nightwing eventually.
I also liked that Amy now knows definitely that Dick is Nightwing, and I'm looking forward to how their friendship will survive this, especially since at least the cliffhanger suggests that she won't have Dick serve on the police force any longer. It's obvious that Dick has become far more attached to his police job than he wants to admit to all his "vigilante" friends and family, who all urge him to quit once again now that the worst of police corruption problem is resolved.
I have to admit that in Nightwing #82 I had some problems to follow how the plot with Arnot the evidence money etc. was resolved, though I got the gist when Dick explained it again to Amy. The set-up for the next story arc (at least I assume that's what it's going to be), that is the scene with Blockbuster getting a video of the highway pile-up, confused me a bit. I mean, I remembered the pile-up from the Nightwing 80 Page Giant, the one where Hella first appears (published around the same time as the issue where Mrs. Desmond dies, i.e. Nightwing #50), but didn't recall it being a contributing factor to Mrs. Desmond's heart failure, thus I checked out whether that accident occurred on the route mentioned in #82 (it does, both times it's Route 61), but then I remembered (okay, I admit it, I had to check the regular Nightwing issues before NW #50 when Blockbuster learns of his mother's death ;) that in Nightwing #49, in the issue with The Sylph, there is also a pile-up (on Route 61 as well it turns out), but I didn't connect that to her death either. My problem might be that I haven't read the BOP issues after the ones published in the Hunt For Oracle TPB and the Blockbuster story runs concurrent in both series at that time, so I'm still missing half of the picture.
Anyway, trying to piece this together left me confused and itching to track down those BOP issues (which would help resolve my dissatisfaction with the "ending," read cliffhanger, of the Hunt For Oracle TPB as well), especially now that it seems like this is going to play at least some role for the next story line.
So (as usual) Venn Diagram reminded me once again that I'm still a newbie, who's ignorant of large portions of canon and not getting all nuances and references, but I still had lots of fun reading it.