While I have thoroughly enjoyed both formats - and very much so - I must admit that my experiences online have been *much* more positive than onsite instruction. Let me try and elucidate:
1. While in the onsite classroom you have the opportunity to think on your feet and challenge and be experiential on your feet to reactions to the students who speak, in the online classroom, you are able to meet *every* class member and challenge their minds and ideas. The students who would normally be lost in a classroom of 35-40 are met and developed each day or week at their level and pushed to consider ideas they might not have considered.
2. I am able to reach the entire class through multimedia exhibits in each of the weekly units - journal articles, non-copyrighted film clips (and many from our university's purchased collection under an agreement for both onsite classroom and online classroom use), photography, art, patents, etc, that the students would not see - or would otherwise ignore - in an onsite classroom. We incorporate this information into our discussions and make it part of the larger whole of history.
3. Each student and I - on the phone during office hours or in e-mail - discuss the creation of their term papers - and discuss midterm and final "anxiety" issues - and as they are used to the online format, and regular communication with me through the discussion boards, they respond much more readily than onsite students, whom I have found I have to pressure to talk to me.
4. I am able to accommodate students from around the country - and around the world. I have had enrolled in my class students from Japan, Indonesia, India, England - and many other countries. As a result, I have set up a *very* specific Skype address *only* for use of my students. They are required to set up the time and day with me ahead of time and I need to approve that request, but for them (and for some of my students scattered all over the state and US), the face time is invaluable in helping them feel "connected" - and I am more than happy to offer it.
5. As the software upgrades, the possibilities of what I can offer become more and more amazing, and the ease of use for both me - and for the students - becomes astronomically better. Many have never known the software, so they don't notice it - but those who have taken online courses before cheer it on. Software does not achieve backwards.
As very few of these issues are met by the onsite classroom, I am leaning more and more toward the online classroom as the better mode of instruction. Yes, there are times I *really* miss the onsite opportunities, but then I think of the above distinctions and realize that yes, I am where I should be, and virtually *ALL* the students are getting far more for their money than they would get in an onsite classroom.
This is the wave of the future, and it holds such amazing promise. Already I think we are seeing clear and fruitful results, and if academics receive effective - and continuing - instruction and support from the very beginning, I cannot imagine why one would ever go back. The only reason I can think of *not* doing this is if the instructor has his or her *own* fear of computers. Beyond that - please, please jump on the bandwagon, swallow your fears, and learn how to do this with vigor. I don't think you will ever be sorry.