The utility of the degree will depend on the quality of the college awarding it. Some very fine universities are teaching their MBA online (Duke, UMass, etc...) and some very poor universities are also teaching online (you've seen some on TV commercials).

It's all about the quality of the institution and not so much about online vs classroom. Everyone and his brother is teaching online these days, especially at the master's level.

Now, if you don't have time to attend class - question whether you have time to complete a quality MBA. The time I spent in the classroom was nothing compared to the out-of-class time for those classes. The few courses I completed online (for the MBA) were not less time consuming than their classroom counterparts - in fact, they required even more time. That has been my experience at all levels in all subjects considering online vs classroom.

You may find that courses grounded in theory (org behavior) are much easier than practical courses (finance) done online. But, those theory courses tend to be heavy on the research and paper writing side.

Online classes give you the distinct advantage of location flexibility and time flexibility. You can do the work from anywhere at any time. They don't offer an advantage of ease or time consumption. The reason that they don't is because they absolutely require that you read the texts yourself (no lectures) with self-study and the assessment method usually involves extensive paper writing as opposed to the classroom common 'multiple guess quiz'.

Online classes require more of my time in a given week than does classroom instruction. That said, I much prefer 1) the flexibility of online and 2) the individual pace of online.