While I applaud the effort that's gone into this, I urge people to consider (and use and contribute to!) Firefox. It's one of the last truly open-source browsers - both in terms of source code visibility (which Chrome(ium) has), and in terms of being able to contribute (which Chrome(ium) has not).
Mozilla is not a club of like-minded hackers that try to keep the web livable anymore. They're a large company now with corporate salaries and expensive furniture and a prime real estate office that values advertisers over users. Firefox is their money maker.
Chromium is a Free Software version derived from a proprietary browser. The people who made that happen must have had an idealistic motivation, or otherwise it wouldn't exist.
Both browsers are libre license-wise, which is a good thing, but in my opinion Chromium is less likely to be used as a marketing stick against users, since the marketing stick version of Chromium already exist. As such using the Chromium browser is preferable for me, since the intentions behind it are likely to be more in line with a free Internet in spite of its proprietary origin.