1. Login and logout of the Learning labs is iffy at best.
2. The ability to pull up every device in CLI is not guaranteed, and if you lose the ability to get to a device, see note number 1, as that may also come into play, and the only way to get that device back is to logout, then log back in to the learning labs. So then you need to close out your browser, and start from scratch. Internet explorer 10 appears to work the best with the Learning labs, as compared to Chrome and Firefox, believe it or not.
3. I hope the test doesn't have any labs as extensive as these, but you can't fault them for creating relatively real case scenarios. My Switching knowledge will be much higher through repetition after completing these labs.
EtherChannels are interesting, but the CBT nuggets videos are a little bit sparse in emphasizing some things that are relatively important. I had to go back through a couple times to catch the thrown out phrase, that then led me to the Cisco book section that illustrated what I needed to know.