Pros
In my opinion, the best things about CognoLink are the learning and the people interaction (both internally, but moreso externally). Working here gives you the opportunity to learn about markets and industries you didn't even know existed. You have the opportunity to hone your communication skills (by email, phone, and in person) with clients (high level hedge funds and private equity firms) and with industry experts at the highest level (you'll talk to c-levels of major public companies). Furthermore, as a relatively young company you can move forward exceptionally quickly (with the right amount of drive and effort, of course). The company is primarily composed of self-motivated 20-somethings who like work hard as individuals and as a company, play hard, and have a good time.
Cons
The work is dynamic and changes constantly, which is a plus, but I hear that some people find it can get monotonous because at a very basic level you're doing about the same thing every day (surely not unique to CognoLink). The hours can be long (not i-banking long, but not public sector either), and a strong emphasis is placed on being self-energized. People who do not do well at CognoLink are not extroverted, not motivated enough, and most importantly not willing to go the extra mile.