Extremely difficult to justify given the great synergy between Stealth and The Turning Wheel, and the additional costs to use this. Shapers would be using it almost exclusively for HQ, but then why not just play HQ Interface if you need that effect? Or The Gauntlet? You'll save credits and influence. Criminals would be using it for R&D, but at 2 stealth credits per use, that gets extremely expensive very quickly, and Criminals don't get Net Mercur in faction, nor get to be Smoke (note that DJ Fenris doesn't gain the Stealth subtype even if he copies Smoke.)

So the only case I see this being used is in a Criminal Stealth deck with access to a huge surplus of stealth credits that can't afford influence for R&D Interface or any other R&D multiaccess for some reason. But then they're probably spending a bunch of influence on stealth credit sources, and they could shift some influence away from stealth credits toward R&D multiaccess. One R&D Interface or two The Turning Wheels would likely be enough.

With the additional costs and the 3 influence requirement, I don't think this is playable.

A major downside to Guru Davinder is that even in the optimal case where you can afford to pay out the ears to prevent damage, you can't steal Obokata Protocol (or an agenda protected by Ben Musashi.) If you expect that, but still want to play Davinder, you'll need either Film Critic or Whistleblower to get around the steal cost. Imp would let you put the agenda in Archives for a later steal, but isn't a permanent solution.

He's also much more efficient dealing with large packets of damage, such as Urban Renewal, Snare!, Psychic Field, City Works Project, or Punitive Counterstrike. Lots of small bits of damage will quickly consume your bank account, but paying to prevent 3+ damage could be well worth the cost. Worst case, let him trash himself and at least you prevented something.

Relevant Ruling: Nisei Comp Rules 1.15.1.b: The Runner cannot pay the additional cost to steal Obokata Protocol while Guru Davinder is installed, because the Runner could not currently take 4 damage if instructed to: Guru Davinder’s first ability would prevent the damage.

As of Downfall, setting up 5 or 6 installed cards with the same cost is surprisingly difficult in practice. Realistically the cost must be 1, 2, or maybe 3. Otherwise it's too resource intensive to set up, and the number of cards of a given cost drops quickly beyond 3. Ideally there is a core installable (or more than one) that you intend to install multiple copies of. E.g. Tech Trader, Gang Sign, Akamatsu Mem Chip, Clone Chip, NetChip, and Power Tap are all cheap and can be central to the game plan. There are also some generic cards of those costs to throw in, like Astrolabe, Bankroll, Datasucker, "Baklan" Bochkin, Beth Kilrain-Chang, Hippo, Kati Jones, Rezeki, and The Turning Wheel.

However, if your deck happens to align with those constraints, it is an incredibly efficient R&D access card for mid-late game. Seeing up to 6 cards makes seeing a value target extremely likely even in a sparse R&D. Shuffling afterward means no need to wait for the seen cards to filter through HQ to see fresh ones, R&D remains just as porous afterward. A forced shuffle is a rare effect, which you can use strategically, such as immediately after a CBI Raid, akin to old Keyhole runs. And unlike Indexing, you only need to run once to access what you reveal (with no possibility of being interrupted.) It's only 2 influence a copy, which means it can easily find room in Anarch or Criminal.

Despite a few advantages, it's clearly not as powerful as Indexing was. Reliance on installed cards means you can't blitz R&D with it turn 1. Shuffling post-access means you're left with no information about what the corp will draw afterward. Accessing one card means that even if you reveal several agendas or crucial trash targets, you only get to access one, and if it has a steal-restriction then you can't try again later (this can be mitigated with Film Critic.) And there's the fact that it costs 3 credits.

Because of its restrictions, I find it unlikely that you can build a deck around it like you can Insight + Top Hat. And you don't need to, there are other options for R&D pressure. But if you're building a deck, take a peek at your install costs. If you're already close to critical mass, consider the pros and cons of tweaking it to allow for a powerful and efficient R&D access event.

Sort of like a runner Genotyping or Preemptive Action. If your deck is empty, this is pretty amazing, you can get back 3 extremely high-value cards. However, it's 2 influence outside of anarch, which could have been spent on a high-value card in the first place.

Drawn early, it's awkward, since the selection options are limited and the reward is delayed significantly. Drawn late, it's great! So its value is highly variable, and works well with other cards that give it alternate value, like Patchwork. Pitch it early, use it late.

Levy AR Lab Access is better if you expect to reliably burn through your deck, but is restricted in most formats. This could be used to supplement that, helping evade the unfortunate situation in which all your Levy's and Same Old Things are in the heap. Alternatively, it's great when you have a specific few cards you want to recur, like multiaccess, utility, or disruption (e.g. The Maker's Eye, DDoS, or Apocalypse.) Burst economy like Sure Gamble isn't worth nearly as much, because you're already spending a card to put them back, similar to using Same Old Thing.

In my opinion, it's very well designed.

Watch the World Burn has two primary uses: trap disarming (this removes the trap from the game before it can fire) and countering asset spam (avoid trash punishment/cost.)

The first is exemplified versus Jinteki Biotech: Life Imagined that's running Cerebral Overwriters, Mushin No Shin, and 5/3 agendas. If they Mushin out a card and advance it, you're usually stuck with gambling on whether it's a trap or an agenda. Watch the World Burn eliminates that threat, letting you run it without fear. But not only does it remove the trap you access from the game, it also makes you immune to that trap for the rest of the game.

The second is obvious against NBN: Controlling the Message, avoiding the trace, and getting a discount on trashing expensive cards. Being able to do it on all subsequent copies lets you cripple a part of their gameplan. Just beware of passing through a Data Raven on your last click (this event is a terminal, so you won't be able to clear tags afterward.)

Even if the card you remove has a trash cost of 5, you still only save 2 credits, which is a bad return on investment. So unless the remove-from-game ability or the all-copy removal are relevant, as it is in the above scenarios, it's not worth using.