Just like everything Online and Traditional classroom environments have different pros and cons that vary from student to student.
I believe online environments offer students to ability to share with their peers with out being judged, which creates a sense of belonging. From my own personal experience I can tell you that it is hard to discuss certain things in person especially if your opinion is not fully developed or differs from others.
As more and more online classes are offered the more teachers and students are using them to their fullest. I can remember my first online class in 2000, it was an absolute joke. The instructor didn't have much structure of a class hardwired into it. I believe the only way the class will be effective is if the instructor has meaningful and worthwhile assignments. Therefore, having pros and cons with each different online class will vary drastically.
I do agree strongly with the article about not letting online classrooms replace traditional classrooms, because I think that traditional classroom are also extremely important to different learners. However,online classes definitely benefit those that can be self motivators and need the flexibility within the courses.
I am not very familiar with online classes in the elementary or secondary schools and how they are use or how effective they might be. I am writing and thinking only on a college level.
Funny enough I was suppose to take this class in a traditional style environment and was given the option to do as an online class. I jumped to the idea of online because it was conducive to my home schedule (definite PRO).