Two words: Face. Splat.

At 2 Strength for 5, Saisentan is an expensive rez, even among other Sentries. It's closest companion is Neural Katana which is 1 more strength, for 1 less to rez, though 2 fewer subroutines. And that difference in subroutines makes all the difference. If Sensei-tan didn't have it's Encounter power, then it's a question of Strength cost vs Break cost

Some notable examples include:

Mimic breaks Katana for 1, vs 3 for Sai-sentence.

GS Shrike M2 breaks both for 4.

Ika breaks Katana for 3 vs 2 for Caeser-Ten; assuming already hosting.

Shiv actually has an easier time with Sailly-senten, requiring only a couple fellow breakers, or even fewer with a bit of boosting to crack all three subs.

The summary is that the credit tax to the runner is roughly the same, favoring Sentai-san only where breaking is more taxing than boosting, typically with static breakers; though I'll leave an in-depth comparison as an exercise for the reader...

But there's a wrinkle in all this I mentioned earlier. Thaisentan isn't actually JUST 3 Net damage. If allowed to fully fire, this card will land up to 6 Net damage. SIX. Realistically, it'll probably only land 4. Only.

Which brings me around to my initial two words. If you can pay for the rez cost, this cards puts an unprepared runner to well within flat-line range. In-Faction, this is a dangerous little Sentry, with a premium price to pay for it's premium package, and at three influence, it's probably not going to see use outside Jinteki, though a few of you will probably prove me wrong.

All this being said, is it worth the slot? From me, it gets a firm Maybe. It's ability and subroutines make it physically painful to move through, and while it's always going to be cheaper for the Runner to crack than for the Corp to rez, it makes an excellent face-blender in the early game. If you can afford the cost early enough to make it worth it, much like another high-rez-to-low-strength Sentry... Well, you're probably not looking to win by scoring.

It's Biotic Labor, except it costs 1 less and the runner can trash it because it is an asset. Actually though, because you need to install this friendly bioroid before he can get to work, you are essentially spending 2 clicks... to gain 2 clicks. So the strategy is installing Bass and using him on a later turn. This makes Bass less attractive than Biotic, despite being 1 less credit.

Of course, being an asset also has a few upsides. He can be reinstalled with cards like Team Sponsorship, rezzed more cheaply with Breaker Bay Grid, searched with Tech Startup and can be used in combination with Biotic in MirrorMorph. He is a combo player's dream, and I imagine people will continue to do cool things with him. Also, he is "only" 3 influence as opposed to Biotic's 4.

So yeah, less straightforward than his operation equivalent, but also wilder.

Týr, Tithonium, Anansi, Thoth... The list of powerful, expensive, and painful to facecheck ice goes on. Each corp has access to at least a few, while a couple of them just can't get enough of the things. So what's the caveat with ice like this? Well, as mentioned above, the stuff can be expensive; even worse, it might be unique. And while that's all understandable for "balance reasons" or whatever, who wouldn't love to have the money and ability to put two Týrs in the same remote server?

Well, Ganked! doesn't completely solve that problem, but it sure helps. You know what's almost as good as two Týrs on the same remote server? Making the runner hit that single Týr a second time after they touch the Ganked! they thought was a Project Vitruvius. Or having Ganked! in there with an actual Project Vitruvius, and laughing to yourself as they trade an agenda score for 2 brain damage, you getting to wreck an integral piece of their board state, and three credits. Depending on how much they paid to get into your server in the first place, that's the kind of tempo loss that'll seal a game.

Doesn't have to involve your remote, either. Give them a second dose of the DNA Tracker that's protecting R&D during a deep dig, or slam into multiple Afshars when they Legwork. Make the Sneakdoor Beta run that they thought would be ice free Not So. Make them encounter Komainu a second time, with twice as many subs (I smell net deeeeeath~). Combining it with Konjin allows you to force the runner to encounter a piece of ice in a different server twice, all in the same painful run. There's so many possibilities, almost as many as there are ice, unsurprisingly enough.

So at only two influence and with no actual credit cost (Outside of the cost of rezzing ice you were going to rez anyway, right?), keep this little ambush in mind for your next glacier deck. Depending on your ice spread, this thing could be nasty. Of course, getting Ganked! often is.

If you have rules questions about this card, you are not alone. To answer your question, this card should be officially errata'd to read: "As an additional cost to steal Obokata Protocol, the Runner must trash 4 cards from his or her grip at random." All of the rulings support this errata.

A 4 strength sentry with 2 subs (ideally 3) for 4 credits is great value for the corp. However, because of the traces, even if the runner face checks this, there is no guarantee it will actually fire. Trace 3 is just high enough to be relevant, especially now that Power Tap and a whole assortment of link cards are rotated. Outside of Sunny, who laughs at this card, and maybe link-friendly shapers like Kabonesa and Lat, there isn't a runner who can brush this off. And being able to trash a console is game-winning, while it can end the run as well.

Pretty decent card, especially if you can park it on HQ. Probably best in Earth Station. Not fantastic though.