I've always like Silhouette. As @Kikai mentioned, the 40 card deck size is rather rare and quite valuable, allowing you to get your essential pieces in play quickly. But I also really like her ID ability.
Expose is an underutilized mechanic. Deck slots are tight and there is often little or no room to include an expose mechanism. And many times that is fine. You may not need it every game. But often it is crucial. I've long had an issue with Mushin. The gamble this forces on the runner has tremendously high stakes. The corporation could score a Vanity Project next turn, or do four brain damage, or eight net damage. If any of these things happen, the corp has likely just won. High stakes are fine; that is often what Netrunner is about. But Mushin does this for free, while saving 2 s, and most importantly, can be done on turn one. Anyway, Mushin is mostly a dead draw versus Silhouette. A few corp decks revolve around Mushin as their sole win condition, so you may get an easy win in such cases.
Recent additions to the card pool have made her ability even more relevant. The biggest example is NGO Front. Glacier has become popular again thanks to cards like NGO Front and Jinja City Grid. Whether the runner takes the bait and wastes 15 s or not, the corp still profits. Knowing whether or not to commit to running at that huge server may end up saving you the game.
Everyone's favorite turtle is at home in most decks, but gets a nice boost in Silhouette. You will often end up scoring two counters on a successful HQ run. I'm not sure if she is holding Blackguard or Zamba or something else in her hands, but either synergizes nicely with her ability (with Zamba being far less janky). Both cards make her ability useful even if you don't find you need the extra info in a given game. I like to use a Sneakdoor to make those HQ runs easier.
Try her out. I think you'll find she does well in the current meta.