Nobody said that this course and Web Development in general are easy... it's a demanding and challenging course...! And that's just fine!!!
I selected this course right after I completed the Coursera course "Web Application Development: Basic concepts" from the university of New Mexico, because of the Ruby on Rails I learned there... It seemed (and it was) the right path to go!
Ruby on Rails: An Introduction is the first course of the specialization and well... it's somewhat hard!
It was great for me, but it's pretty demanding and challenging for an introductory course.
The word "introduction" may be misleading but the one and two-star reviews are misleading as well, because the course IS NOT for beginners...
I study Electrical and Computer Engineering, I've been a Linux user since 2009 and yet I spent much of my time troubleshooting and searching on stack overflow... (I completed the course in less than 10 days...)
I've read reviews from previous students and I agree that there could/should be an extra week or two for the Ruby language and syntax and/or split module 3 in half to have more time to absorb the tons of information and course material.
That being said, I found the course very well structured, the instructor was very helpful as he answered in every thread in the forum and the assignments, though challenging, were well documented. The only problem was with the last assignment and the food2fork API, as the service was down for a day or two and couldn't sign up for the API key...
As mentioned above by other reviewers, YES, testing with rspec was a huge bonus!
Application deployment on Heroku was another plus for the course!
Another plus for the lecture on the bundler and the gems!!!
Demanding and challenging but also a really great course!
P.S. When "rails s" fails, use "bunlde exec rails s".