Projects in Bimodal mode, what is you experience? Your opinion?

First of all, Agile and Waterfall are not matter of comparision. The first one is an approach and you can apply that approach with any process life cycle. The second one is a project life cycle process. I was the leader in 2003 of a hugh project that wins a PMI's award. The project includes the whole enterprise architecture transformation thru the "on demmand buisness" model. To do that, we have multiple programs/projects running at the same time where we use the approaches, life cycle models, life cycle process, methods (including our own methods) to create the whole solution. The conclusion is simple: nothing new behind the sun if you really understand what to be a program/project manager is. The problem in general is people, including those that earn a certification, do not understand that. The acid test is simple: putting the question "what is a project manager?" and you will surprise.