Unless you plan on using this card like 5+ times, Imp and Stargate are a hell of a lot better and don't take up a console slot. But... at only +1 MU, this card limits your ability to play cards like Stargate and Imp. So you're making a huge commitment to discarding a LOT of cards from your hand. Problem: most of the cards that you'd be discarding, are better than this card.

There's no price at which this would be a good card. It's asking a console slot for something which is provided more effectively and cheaply by cards that don't need the console spot or discards. 4 credits is way too high to consider this in standard. As long as Imp is available, I think $1 would be too much to pay for Carnivore.

Consider: Maw costs 6 credits and offers +2 MU and an okay trash ability, and it's probably overpriced relative to other consoles. (In particular, Keiko costs $3 for 2MU plus occasional $1 gains, and both of these play well with Stargate and Imp). If you wouldn't pay $6 for a 2-MU Maw which reaches into HQ and trashes cards on its own, don't pay $4 for 1-MU Carnivore which only affects cards you've already paid to see).

Compare this card to a 1/3 agenda with a weak effect, like Water Monopoly. Except, instead of a 1/3 agenda which makes a weak effect last forever, this is a 0/3 agenda which makes a weak effect last for maybe 1 turn before it gets trashed. This is one of the worst assets ever printed.

In the 3 clicks it took you to install and use this card, you could have clicked for 3 credits (a larger credit swing than you'll get from this card), OR you could have rummaged in your jankpile and pulled out TechnoCo. Your call.

Borderline playable. It's kind of expensive for an ice which is mainly useful early and doesn't hold up well against most common killers. Jinteki decks tend to run slower and poorer than most other factions, and $4 will be a problem for Jinteki more than anybody else.

I don't think this card has the support right now to create early opportunities. E.g. back when Mushin No Shin was legal, installing Karuna on a Mushin'ed card (especially a SSL Endorsement) would have been a high-value turn 1. Without powerful support like Mushin, Karuna costs a lot of $ for an early-game ice. Jinteki doesn't have a lot of cards I'd want to protect early with a Karuna, and those cards usually work better with Whitespace or Vanilla. Turn 1-2 Rashida loves Whitespace.

Startup View. Comparison to Ballista:

Win is cheaper, more expensive to break due to having 1-2 more subroutines than Ballista (only with Odore both are equally expensive) and can fire multiple subroutines. Win wins. On HQ Win wins even more. It's not even fully boomerangable. Add to that the awkwardness of Ballista's single subroutine which never allows you to trash a program AND end the run. Add to that that Win can do both AND trash Hardware in addition to that.

Devil's advocate:

1. Winchester cannot end the run if not played on HQ.
2. A VERY rich runner can "break" Winchester without a Killer installed due to the subroutines being (tho quite expensive) traces.
3. Ballista is more splashable due to only 2 inf compared to 4 with Winchester.
4. Winchester is more predictable to be played on HQ/should not be installed on HQ if HQ is already "full" of ICE.
5. A facecheck without anything installed is worse with Ballista, which has a hard ETR.
6. Link-heavy Runners laugh at the traces.

Answer:

1. Pity, nothing to do about that.
2. I have to go a little out on a limb here: Rich facechecks aren't really a thing. That's why cards like Whitespace work at all. It would make a difference if you already trashed their last Killer but we're already at a lot of "if"s. Even if they facecheck while being rich (another "if") they'll pay a lot - I'm fine with that.
3. How often do you see a Ballista outside of Weyland? o.O
4. Reading this review should have made clear that Winchester is better even if not installed on HQ. If you think predictability is a problem you still get more worth installing Winchester somewhere else.
5. Agreed. Win...loses :( But paying 5 for an early ETR hurts like /%$&. And if you really need the ETR on Winchester you can buff it with your own money.
6. Most of them are not really the meta-winners in Startup right now. Even if they have 1 Link AND Win is not on HQ they have to pay 5 credits which is still more than breaking Ballista with contemporary breakers.

I felt kinda sick everytime i played/saw a Ballista for 5 credits and saw it being broken for 2 credits by a Bukhgalter. That's what drove me to writing this review. I'm not trying to bash Ballista here but I'd really like you to try this: Substitute the Ballistas in your decks as far as you can with Winchesters. Tell me how you feel about it. You can go back if points 1-6 (or something I didn't think about) happens too often. Just give a little love to Win. The review on here makes it look bad which it isn't. :(

Forms a neat combo (as most things do) with Anoetic Void. If you put a single click into Cold Site Server, the runner will have to spend the click to run the front end multiple times to get in, frequently capping them at just two runs to enter. If you click Cold Site twice, a runner who gets bounced by Anoetic once literally can't get back in, unless they are somehow getting extra clicks. Admittedly, this does use a lot of corp clicks to function, but with something like MirrorMorph: Endless Iteration, as mentioned in Cpt_nice's review, you can make a pretty darn chunky server! Usually, though, Anoetic Void + Manegarm Skunkworks is tough enough to break as-is. and doesn't require such consistent upkeep.