Overall, I believe the Pros exceed the Cons, but I 'll start with the Cons first and close on the positive note. If you don't want to read the full details, I've summarized at the bottom.

CONs:

1) Might have to wait a day or two to get a response from your teacher.

2) Email conversations can easily get confused, sometimes you could have a 2-minute conversation what might take 5 or 10 emails to clear-up. However, most schools will provide you with phone or Skype access to the professor.

Writing skills become very important, i.e. you must communicate clearly in writing.

3) If you're a really people person, you might find the online class rather cold and sterile, but on the other hand use of discussion boards, rosters, email, etc... can still provide a social outlet.

4) Most online systems have a class roster, where people can post their pictures and their profiles. One student posted a huge full size picture that was so big you had to scroll to see the whole thing. So, in this case, students need to have avatar style pictures ready to upload (pictures of the students with the grandkids may or may not be appropriate). In other words, not all students have the proper idea of online etiquette.

5) You have to be somewhat technical. If the teacher tells you to send a .gif not a .jpg, you need to know what that means. Or maybe the teacher wants you to fax your homework, then you hvae to find a fax machine. Or will the school allow you to scan it, and if so to what format?

Catch my drift? I was taking a Hebrew class online, and one day the school fax was not accepting it, so I faxed it to myself, which converted it to a PDF. The teacher would not accept the PDF, insisting on a .GIF so she could grade it with her electronic pen/tablet, and send it back.

6) Hardware/software/internet failures can be a pain. If your internet is running slow, or you don't have good internet access, an live connection with your teacher and fellow-students can be almost worthless. I remember on "live" session once. I was in a hotel, and the internet in my room was causing problems. The hotel support suggested I go downstairs and use the wireless in the lobby. This was a language class with a live voice connection, but I could practically not here because the kitchen was cleaning up from the hotel's evening dinner, banging pots and pans.

When there are issues on the side of the school, you must contact their technical support, and typically wait one day for a response.

7) Just because the class is online, doesn't mean there are not deadlines and finals. The final might come during a week where you have business presentation due, or a family vacation.

Example: In the recent Master's level class I was taken, we didn't have a final exam or paper, but we had to translate material, than write essays on each section. I think the entire process took me over 40 hours, which consumed my entire week, and even dug into my work schedule. I thought it was grueling, but I did learn a lot.

8) Without the human touch, you may not have an idea of whether your or doing well or poorly in the class. It never hurts to contact the instructors and ask.

9) In a Masters or Doctoral program, there is often a week or two of the year, where you can physically go to campus and take one ore more classes. This is often required (and can be very expensive on travel if you live far away).

PROs:

1) In today's world, commute time and gasoline savings are a big deal! (I recently heard of a school in Oklahoma that reduced its 3-day a week classes down to 2-days a week in order to save the commuter students on their gasoline bill.)

2) An online class might be the only way to take a class in a specialized field. Or, you might live in a small town, far away from any good college. Even though I live in Dallas, and there are many college around here, I was interesting in taking and advanced Hebrew class.

3) Or, perhaps you travel on your job, or because of other duties, you cannot attend class on a regular schedule. Online classes, like recording TV allow "time-shifting". Typically you can work on the class whenever you want. HOWEVER, some online classes do have a weekly schedule and deadlines.

The Hebrew class I took online, and others, have required an online session with the teacher and one other student. We had to pick a time that was suitable for all of us, across various timezones (and even countries), which was challenging. But this give us almost one-on-one time with the professor/teacher, and allowed us to practice our newly acquired language skills.

4) The discussion forum can be very interesting. We've all used discussion forums on the Internet, but most of them are public, and their's so much junk there. In a class I recently took online, the professor said that "the book of the lifting" (i.e. the core of the course) would be done in the discussion forums.

Each week he would post assignments, and a series of questions (or translations in the case of this class). Use of the discussion forum was about 40-50% of the grade. We didn't have to answer every question, but I had the idea he had a log book, and when you made an interesting comment, he would put a little plus by your name.

The real "pro" fo the discussion forum was that you had time to think about your answer, but the "con" could be that it took a lot of time to think and answer, and that answering each question, even if only a paragraph or two, was akin to writing an mini-essay.

Our professor often instructed us to answer the question first, without reading the other students posts, and then to read their posts, and make further commetns.

5) Students online might be older and wiser. They often have jobs and families and real-life experiences to bring to the class. You might learn more from them than the typical college student.

Classes I've taken online at Hebrew College in Boston:

1) Hebrew IV

2) Hebrew V

3) Readings in Agaddic Literature

4) Genres and Themese of Biblical Literature

Other Information:

Most online classes rooms use a software such as Moodle (Open Source) or BlackBoard (commercial). With BlackBoard, you can purchase the "BackPack" add-on which allows you to download everything, and work offline part of the time. I have created my own video/tutorials that teache how to use Moodle. See http://CMSTrainingVideos.com.

Summary:

CONs:

1) Waiting for responses

2) Emails slow and confusing sometimes, need good writing skills

3) Lack of live people contact

4) Putting up with non-technical students and first-timers

5) You may need a few technical skills yourself (to survive)

6) Hardware/software/internet failures can be a pain

7) There are still deadlines and finals (at unopportune times)

8) Maybe lack of feedback to your performance

9) Perhaps an expensive on-sight visit required annually

PROs:

1) Time and gasoline savings!

2) Only way to get specialized class

(or only way to get any class if you are very remote)

3) You can time-shift the class to what fits your schedule

4) Interesting discussion forums

5) Students might be older and wiser, better experiences