Interesting site. Only thing I would change would be to find the attack cost based on block time. Ethereum has a block time of 15 seconds whereas Bitcoin has a block time of 10 minutes. This changes the amount of damage that can be done in a given amount of time.
Nice! I didn't realize you were on HN, I've sent your site to friends before. I'm curious -- has your traffic increased or decreased lately (due to the bust)? Do you track your traffic or graph it at all?
I track it via Google Analytics -> here's a screenshot of the last few months [0]. Traffic has been pretty steady over time with a few spikes from Hacker News or Twitter mentions. I believe the most recent spike in traffic is related to the 51% attack against Vertcoin [1].
