After I revamped my blog and made the fonts bigger, I reconsidered the fonts I use, and how they are delivered.
I found Noto Sans, a font derived from Droid Sans, which I'm sure is derived from Open Sans. It replaces Open Sans as copy text on my entire blog. (You're reading copy text right now.) I chose this because the capital I and lowercase l are easier to distinguish, and the lowercase g only has one bowl in it (less fancy).
For monospace text, I finally switched over to Cousine. It replaces DejaVu Sans Mono. Historically, I used DejaVu as my "programming" font. I came across Cousine a few years ago after starting this blog, and loved it. I have fully switched over to it (except for this place), and I don't use DejaVu unless Cousine isn't available. Both are great fonts to read code in, but I like Cousine better, because the smaller parts of lowercase letters are taller (known as x-height).
I have done a blasphemy, and retained Questrial (a non-Matteson font) for my headers. I love its perfect geometric forms, and I admire its lowercase a.
I was serving all of these as WOFF files. But through the magic of data URIs, I can serve all of them included with my one CSS file. Now my CSS is about 100k, but it covers what used to be four requests. So now if some Secret Service agent is doing some clandestine operation with his satellite phone, he can spy on my site faster. I hear the lag on those is enough to blow up a pressure cooker.