This is my first experience with an LF training course, and I am underwhelmed. The writing quality is meh, unclear and with poor examples, and the Cosine lab environment is unusable. After multiple tries over several days I am unable to install Devstack. stack.sh fails with a "stack.sh: [[: not found" error, and the Cosine environment loses the connection frequently. Sometimes it loses the connection entirely, sometimes it loses only keyboard input despite displaying 'Status: Ready'. Providing a non-persistent lab environment would be OK if it worked at all. I'm going to try a local Devstack installation. If I had paid for this course (I got access for free) I would insist on a refund. I suggest not launching courses until they actually work.
LF also needs to get rid of the crappy Captcha. Being forced to wade through tiny blurry images is like saying you don't want anyone to post comments, and it's nearly impossible for people with impaired vision. I suggest a simple plain text multiple-choice Captcha, if you have to have one at all.