I have a feeling stacking sentries, (especially against criminals), is going to become a somewhat common practice, and quickly.

The efficiency this killer brings is rivaled only by the likes of Garrote, Faerie, Alias, and Switchblade/Dagger. All of which carry some hefty drawbacks. (Expensive and 2 memory, trash-to-use, centrals only, and stealth credits, respectively.) And while Mongoose has it's own obvious drawback, it seems a lot less restrictive than most of the others. It's also fairly cheap to install, and while slightly inflexible with pumping up strength, breaking 2 sentry subs for a single credit is almost unheard of. (Unless you run what I feel is its only real rival, GS Shrike M2)

At only 2 influence, this is a pretty easy splash, especially if you're packing something else to take care of any stacked sentries, like an AI or the soon-to-be-tested-everywhere Panchatantra + Gingerbread/Deus X/Sharpshooter/whatever.

One interesting note, it IS possible to use a single copy of Mongoose on multiple sentries on a run, if you're willing to pull some slightly gnarly jank to do it. Trash it mid-run either by installing another program at instant-speed, or with something like Heartbeat. Then re-install it with a Clone Chip. Since the game considers it to be a "new" install of Mongoose, you can then break another sentry.

(Also, the most obvious counter-play to Mongoose, (stacking sentries), amusingly makes the arguably-worst-killer-of-all-time, Pipeline, ever so slightly more playable, due to the fact that pipeline keeps its strength through the run.)

"Hey, boss, that card art's ready."

"Looks pretty good... but it's not edgy enough,"

"Edgy?"

"Yeah, needs more gritty cyberpunk."

"But it's a cute tiny giraffe, it's not supposed to-"

"Put some wires or something in her other arm."

"What?"

"Just do it."

"But.... uhh... okay, sure, I guess. Why not."

I love this card for several reasons. First, as already mentioned, it's a solid econ card for Jinteki, something they don't get all that often.

Secondly, and most people consider this a downside, you have to reveal your entire hand to make it the most effective. And while it's true that this can be awkward for Jinteki, it also opens up a lot of great plays that exploit the information given to the runner. The obvious one is to show a hand full of nasty traps. The runner won't be going there any time soon, so you have a bit of breathing room when you do get some agendas in HQ.

The other, I think, has the potential to be even more powerful, albeit somewhat janky/risky.

Show them a hand full of agendas.

"STONE THE BLASPHEMER", you say. That's stupid! And most of the time, you would be right. But when the runner goes for a Legwork, you have a nicely advanced Allele Repression the runner thinks is an abanonded Project Junebug, and you also have 3x Snare! in Archives...

(Or I guess you could try to lure them into some kind of horrible Whirlpool/The Twins/Komainu/Cell Portal/Janus 1.0 jank.)

This card. This card is already one of my favorites.

DaVinci not only saves you a few credits, but it also lets you throw out both hardware and resources at really fun times, instead of just programs like Clone Chip and SMC.

I've picked out a list of cards that have interesting/fun/hilarious interactions with DaVinci, specifically its ability to install most any card with only a paid ability window.

• All three of the shards, as pointed out by daytodave. Mess up scorches, shut down Power Shutdown combos, and nab agendas from archives without the corp being able to do anything.

• Muertos Gang Member to derez things and generally force annoying corp decisions mid-run.

• Wait what? Weyland just tagged you with SEA Source? And you don't have any Plascrete avalible? It'd be a shame if... ya know... the Paparazzi were to show up out of nowhere and ruin their double scorch. A crying shame indeed. (Or you could be boring and throw down your plascrete like everyone else.)

• Use DaVinci to throw out a Street Peddler mid-run, use that to install a Clone Chip, and then install a breaker from your heap. Maximum jank points.

• Install The Source on the corp's turn. Enjoy their salty tears. Point and laugh at the Cyberdex Virus Suite they had ready to kill clot.

• You can pull a Rabbit out of your hat mid-run and dodge nasty trace routines. (I mean, if you have the money, I guess you could just outspend the corp, but Rabbit Hole sticks for afterwards.)

• And lastly, you could install a Security Chip mid-run to help break through unexpectedly strong ice. (Extra points for installing Rabbit Hole with another DaVinci first.)

This could very easily become one of the cards the corp hates to see lying around charged up, even if only because they have no idea what you're going to do with it. It's a shame you have to go through so much trouble to get it ready, but I still don't feel like that should hold it back too much.