DaVinci is what happens when a Shaper tries to run like a Criminal.
See, DaVinci is most similar to Desperado. If you make 5 successful runs with Desperado, you get 5 credits. If you get 5 successful runs with DaVinci, you get to install a 5-cost card from your grip for free. That's sort of the same thing, right?
Well...sort of. There are a lot of differences that make DaVinci a unique animal.
First, DaVinci is not permanent. Desperado makes you a credit a run, forever. DaVinci stops adding value either after you use it, or when you start earning power counters you're never going to use. If you use DaVinci to install a Liberated Account, then every run after the sixth gave you no additional value. The upper limit of value you can get from DaVinci is the most expensive installable card in your deck.
Second, DaVinci is not unique, or a console. You can easily have several DaVincis working at once, earning you several "credits" every run, and can still have a console alongside it. You could even be running two DaVincis and a Desperado at the same time. In fact, you probably should.
Third, DaVinci doesn't give you liquid credits. With Desperado, the credits you get from your early runs can be spent on your later runs. DaVinci gives you nothing until it pays out, and you can't go half-and-half with it; you must have the full install cost in power counters. It could be really frustrating to have 5 credits and 5 power counters, and still be unable to install the Garrote you really need.
Fourth, DaVinci gives you an instant-speed install. This is valuable on its own. You can run R&D with three counters on a DaVinci, and both a Medium and a Mimic in hand, dropping the killer if you need it and the Medium if you only see code gates and barriers. It also allows you to activate Hayley on the corp's turn. It improves the overall economy of the card, since the click you used to install DaVinci is the same click you would have used to install the other card.
DaVinci works best in an ID and a deck built for speed and stacking up "successful run" triggers. It would make a fine addition to the "Andy-sucker-rado-testing" build, but you could also make it work out of an aggressive anarch like Reina or Quetzal, or Kate in-faction, although I'm not sure if Kate's discount applies when using DaVinci. Feel free to experiment--it is a trash effect, which Geist likes, and it lets you install cards from 0 credits, which Nasir greatly enjoys. Just keep it out of Iain, and you'll probably do fine.