I'm in the midst of my program, so my opinion may change from semester to semester
My program had all of us who started together come on campus for a week of orientation prior to our first semester. We bonded very well, and use social networking tools to keep in touch. I think I would have a problem with the all online program if I didn't have such a strong support group to vent to, ask questions to, etc.
As for the online vs. in classroom, I always found that I have to spend alot of time studying outside of a classroom anyways, so I don't have a problem with online. I like it when classes are more individual, do these x assignments, they are due by these dates and worth this many points. I can self-regulated and get the assignments done, those classes are the best for me. Several of our classes have group assignments, or the professors dole out a week (or some number of days) of work at a time, and you have assignments open up on a specific date and close on another date. I don't like those as much as I have to do the work at their pace and that is not as convenient for me.