Just passed the second half of the linux+ today. I wasn't really planning on taking this test until WGU added it to their IT Security degree. I've been doing linux administration for the past year and a half and I've probably used just about every major distro before settling on arch linux. The coursework did teach me a few interesting things that I never learned on the job like the hwinfo utility and the ldd command. My future educational plans are to finish my degree and then focus on another linux cert. I'm considering the RHCE because it'll be more marketable but I feel like I might learn more from the LPIC-2 and LPIC-3. Personally I was only using fedora and centos at the time of studying but I was already pretty familiar with the apt package manager.
Being a sys admin sucks but I love it