Rather than comparing Blackstone to the other stealth fracter BlacKat, lets compare this to the gold and platinum standard fracters, Corroder and Paperclip, for the barriers you might expect to see.

• Vanilla - 1 vs 1 vs 1 - Do I really need to mention this one?
• Resistor - 1 vs 1 vs 1 - Useless if you have enough tags to lose your Net Mercur.
• Wall of Static - 1 vs 2 vs 2 - Though Blackstone wins here, it's not a common sight.
• Hive - 5 vs 6 vs 5 - Blackstone draws with Paperclip.
• Eli 1.0 - 5 vs 4 vs 3 - Looks like Blackstone dislikes our friend here.
• IP Block - 5/4 vs 4/3 vs 3 - You are better off beating the trace unless they boost it or use shenanigans.
• Data Ward - 10 vs 10 vs 7 - Not accounting for encounter tax, but it's either that or break normally.
• Curtain Wall - 9/6 vs 11/7 vs 9/5 - Blackstone performs well here, but stealthiness isn't incredible.
• Orion - 9/8 vs 9/8 vs 7 - Blackstone is on par with Corroder here.

So, Blackstone performs pretty reasonably, but falls flat on it's face against Eli 1.0.

Blackstone, though not really breaking any records, is a totally playable fracter for Smoke, especially if the saved influence gets you another Temüjin, some Employee Strikes, or something else useful.

It is also worth noting that adding Datasucker support also rounds out many of Blackstone's problems, and the strength for the run effect could potentially save you a few credits.

Though Blackstone would not be my first pick, you should probably consider it as an option, even if you do need to make a couple changes to make it worthwhile.

TL;DR: Blackstone is an ok fracter and can be good if you have Datasuckers, but it's not a stealth-tier breaker like Dagger, Switchblade, and Refractor.

EDIT: looking at this card again, with some of the more important and common ice; particularly Vanilla, Eli, IP Block, and Chiyashi (everything else is largely irrelevant), Snowball, which is agreeably one of the worst available fracters, has similar break costs, being the same for Vanilla, Eli and IP Block, and only being 1 credit worse against Chiyashi.

Attack of the Birbs! Peck those sysops' eyes out!

I think that if a deck built around the Birds' derez abilities crops up (which from some of the Red Sands Cycle spoilers, looks like it might... assuming that people care about ice again at that point) then this would be a rather reasonable splash to make; as you can de-rez and trash a piece of ice with this, without giving them the opportunity to rez it again.

But to be honest, it's probably going to see more play with things like Blackmail and DDoS instead.

Dedicated Response Team as an NBN upgrade, so how does it compare?

Pros:

• Upgrade rather than an Asset, meaning it can be protected easily.
• Damage is unpreventable.
• Is in NBN, where getting the runner tagged is more feasible.
• Slightly better rez and trash costs.
• Works before the runner can trash it when running it.

Cons:

• Only effects one server.
• Damage is trace dependant.
• Only 1 damage per Drone Screen.
• Must be rezzed before the run, removing surprise factor (DRT can be rezzed after the runner chooses not to jack out)
• Doesn't work with mid-run tags, such as Data Raven, Snare and Prisec.
• Extremely powerful tag-punishment operations already exist in faction.

... And I was really scraping the bottom of the barrel with some of those pros; so it should be painfully clear that Drone Screen is nigh undeniably worse than Dedicated Response Team, which wasn't a great card to begin with. At least DRT enabled some funny surprise flatlines, whereas Drone Screen will be quite unsurprisingly useless.

Seems kind of hard to make good use of.

The two main reasons are that it:

• Is secretly very expensive; The cost to break the ice is most likely more than 2-4, which could easily pay for a The Maker's Eye or an R&D Interface instead.

• Does not provide additional accesses; Unless the top card(s) of R&D are removed somehow, then you will only be accessing the same card(s).

So, clearly this needs to be combined with some other cards to make it worthwhile, here are a few candidates:

• Temüjin Contract can deal with the additional break cost.

• Parasite and Cutlery will lower the break cost (providing the "open season" the card refers to)

• Vamp can also remove this break cost by removing their credits for rezzing ice.

• DDoS + False Echo can also stop them rezzing any ice.

• Medium gains counters, providing extra accesses with each run.

• Deep Thought and Chakana gain counters I guess?

So I see two scenarios I would bother using this in:

• A Dyper deck, (a deck that uses DDoS/False Echo, Hyperdrivers, Medium and Keyhole to make 10+ runs on R&D for a silly number of accesses.) wherein this is a bad All-nighter for several reasons. (and that's rarely used anyway)

• An Ice-Destruction Anarch deck, where this could allow them to get another run with medium when peeling away ice. wherein this is probably not worth the influence, since you could spend it on Clone Chips instead.

Overall, I don't think this will ever see any real play, unless a crazy card that goes with it appears.

I'll just direct you to tiedyedvortex's review of Algo Trading to let you know how monumentally bad this card is.

The only redeeming feature of this is that if the runner runs to trash this, you can get back the money that you basically wasted on setting this bad card rolling.

Edit: With Tapwrm being the new hotness at the time of this edit, I can see this being a plausible include for CTM if you want to keep your total credit pool low for Tapwrm, but get rich enough to hit the runner with SEA Source into Exchange of Information.

Almost certainly not actually worth doing, but I thought it an interesting interaction that ought to be highlighted, particularly as you can cruelly put it on a Mumbad Virtual Tour if you can spare one to protect this hot garbage.

... of course, Sealed Vault will do about as well here, just be sure that you don't lose everything to a cheeky Polop