3.5 stars.
A few warnings: if you are in search for a cafe with free wifi, CSI is NOT the cafe that you're looking for. Wifi is available to members only (a minimum fee of $30). CSI can also make you feel really drowsy - the fact that the cafe is in a basement, the dim lighting, the couches and cushions all add to this factor.
Apart from suffering without free wifi (and having to resort to using up more of my limited data), I enjoyed the coziness of the cafe and I appreciated the fact that CSI is a very open, work friendly-ish (I added the -ish because CSI only provides wifi for its paid members) cafe with a unique interior design (it's like a cross between a secret lab, an indie warehouse and an exclusive clubhouse). Something noteworthy to mention about CSI: it's very spacious (it's the biggest cafe that I have been to so far) and they allow corporations to hold busines meetings.
The food was also really good - the latte (and latte art) is amazing and the bacon sandwich was super delicious. I recommend coming to CSI if you want to catch up with friends, if you're out on a casual date, or if you want to catch up on work (provided that your work doesn't require much wifi usage).