This card is very powerful, though few seem to have noticed. The Card Talk podcast people noticed, though they didn't rate it quite as highly as I would. (They rated it an average of 3.25 out of 10, where 1 is best.) Here on RingsDB, no one (until me just now) has posted a single comment on this Smoke and Think page. Someone did post about Smoke and Think over on the Spare Pipe page, but only grouped in with the other two pipe events and not really with any meaningful commentary. My internet search turned up those two as the only places on the whole internet that this card is discussed. Perhaps the lack of attention is because Smoke and Think wasn't printed until the second-to-last adventure pack of the entire LOTR LCG universe, so most people don't even own it.
I completely agree with this quote from the Spare Pipe page: "[Spare Pipe] and Smoke and Think really brought the whole Pipe deck archetype finally together." In fact, I'd say it's an understatement. The sheer resource advantage of Smoke and Think is likely too powerful, assuming you're all-in on the pipe motif. For comparison, look at Gaining Strength and similar cards, which trade card-for-money one-for-one. Even the much-loved Good Meal trades at "only" one-for-two and it comes with significant restrictions (Hobbit hero only, must match sphere). Smoke and Think has no sphere restrictions and trades at one-to-X where X is the cost of the next card you play!
How will we get enough cards to use with this abundance of riches? Good thing we have Old Toby, and while Gandalf needed no more help being awesome (see Sneak Attack, Reinforcements, Vilya, etc.), Smoke and Think gives us yet another way to abuse his power. As one simple example, play Smoke and Think then Gandalf to draw three cards (replace the two spent plus one more card, maybe Smoke Rings) for zero cost, and that's just the enters-play ability, ignoring Gandalf himself helping you out for the rest of that round!
The obvious downside of Smoke and Think (and all the pipe events) is the significant setup and investment required before it achieves greatness. To pull off a free Gandalf you first must have five pipes in play, which is no small thing. Make sure you have cards like Beravor (with a DĂșnedain Pipe), GlĂ©owine, Master of the Forge, Daeron's Runes, Deep Knowledge, Heed the Dream, and Old Toby to help bring the pieces together in a reasonable amount of time. Despite the pipe motif being clearly designed for just blue () and green (), if you can manage room for purple () in your lineup, the usual Steward of Gondor and maybe King Under the Mountain (if you're using Dwarf Pipe especially) will also help you accelerate to your payoff.
In summary, even though it seems to have gone unnoticed, Smoke and Think is a secret powerhouse available to those paying attention. Despite its drawbacks, Smoke and Think is my favorite kind of card: big investment for a huge payoff.
Rating: 10 out of 10 from me (with 10 being best)!