I never really liked this card when it got released. It first got my attention when my local playgroup started to use it with Blue Sun: Powering the Future. Blue sun was the hype card around here and of course I had to try my own version. I included The Root in it. I didn't like it. All the time I used it the wrong way...
The Root really shines if you playing with several remote servers, including already expensive to trash cards like SanSan City Grid, PAD Campaign, Marked Accounts or even Adonis Campaign.
I think it harmonizes best with Gagarin Deep Space: Expanding the Horizon. I also can imagine to splash this card in HB decks though.
The most beautiful combinations you can make with this card: 1. Rez it at the end of the runners turn. Use it to rez SanSan City Grid for 3. In your turn use the recurring creds to score an Project Atlas or Superior Cyberwalls for free. This means you got 5 creds back already and still have 1 cred on it for the runners next turn. If he chooses to run for it you can use that 1 remaining credit to rez an ice protecting it. The runner will have to pay for breaking that ice, pay 1 to access it and trash it for 4. So the runner just lost 6-7 creds and a click for the run. You basically lost nothing and the SanSan is still in game. If the runner goes for SanSan instead and doesn't trash The Root you will get another 3 creds/turn. Brutal. 2. Use it to rez your economy assets like PAD Campaign or Adonis Campaign. 3. Protect yourself against Account Siphon by spending 6 on rezing it and use the 3 creds to rez Crisium Grid. The runner won't have money to trash both. 4. Use the creds to advance Fire Wall or Ice Wall to insanity and score big money with Commercialization.
There is just so much potential in this card! A must in all Gagarin decks, and highly recommended in asset heavy decks. Use it to rez Dedicated Response Team for example...