It's definitely not just the design itself. The CTA (your email submit) of the new landing page is better positioned throughout. You have also added urgency ("time until next shipment", "subscribe now before time runs out"). You can also see up to 3 previous candy boxes now, whereas before, you'd have to click through. All of those contribute to the conversion rate of your new landing page.

Your old landing page actually contains some great elements that are missing from the new one, like the reviews, the explanation anime video and the "new tastes only available in Japan", which seems a great feature to me. I'd definitely try and add those back in, and split test that new version against the current winner.

This. Design != Content. Often times, simplified CTA and Value Proposition can have the same effect as a full blown redesign.

Well.. http://3v4l.org/tT4l8

Looks great, but what about validation for the models? Didn't see that mentioned anywhere.

Exactly, use PyCharm for auto-identing and this is no longer an issue. For shells, you can use bpython or IPython to the same effect.

This looks great! Would be awesome if Packetbeat received Postgresql support too.

In my opinion, it implies that QUANTUM has a queuing system.