While it is slightly situational, I think Focus Group is the one card in Downfall that really screams "overpowered" to me.
For starters, let's compare it to the most famous fast advance tool, Biotic Labor. While that operation might be more flexible, giving you an unconditional extra click, it will nearly always be used to score an agenda requiring triple advancement. For this purpose, you are set back 3 clicks, 1 card and 7 credits. For Focus Group, it only costs you 2 clicks, 1 cards and 6 credits, provided you "hit" at least three cards in the grip. If you hit two, it still gives you the same return as Biotic. Not cheap, but also not terrible in my opinion. Let's also not forget this card is harder to effectively counter with anti-FA-best-boy Clot.
But the real strength of Focus Group is in its potential upper limits. Many runner decks consist mostly of events and resources, and having 4 of either on hand isn't that uncommon. And if that happens, you can fast advance a 5/3 from hand. If you have multiple copies it even becomes child's play, while admittedly very expensive. It also works nicely with the never advance game, especially if you have won the game of Beale or no Beale, so that you can get 3 or even 4 points instead of 2.
Obviously the main balancing factor of FG is its dependence on the runner's hand, meaning it can backfire spectacularly. Luckily (for the corp), NBN has a few tools to peek at the runner's hand. The most obvious is Standard Procedure, which was always a decent card but willl become a staple in yellow FA. Peeping Tom and Waiver might actualy start seeing play. Harishchandra got a a fun new toy and I think Focus Group will be good in Azmari too since they have some control over the runner's plays, especially backed up with Scarcity of Resources.
Requiring a succesful run is another drawback, but as most runners will be set up and aggressive by the mid to late game, this card will rarely be dead, especially in non-glacier decks.
A possible counter play the runner has is of course keeping their hand size low, but this obviously carries the usual risks associated with having few cards on hand. I could totally see this card replace Biotic Labor in Jinteki PE decks, especially considering the lower influence. There are also ways to keep the runner's hand full, like Personalized Portal and Pālanā Agroplex.
Looking at the card pool again, I think Focus Group comes out strong in most comparisons. Game Changer and MCA Austerity Policy are technically stronger but take way effort to set up and can be trashed by the runner. Shipment from Tennin is cheaper for 3/1's and 3/2's but it doesn't let you fast advance a 5/3 and you need two copies in your hand for a 4/2. Calibration Testing, with Breaker Bay Grid and Team Sponsorship is also powerful but folds to asset hate.
So yeah, maybe I am overestimating the potential of this card, but I think it will be a serious problem for the upcoming meta.