My general concern with online manuals is:
1) Restricted access to internet connections
2) Limitations on PDF for printing or extracting page
3) Sometimes the format they are offered is a "reader" type interface which can lag and or have restrictions with screen shots
I like hard copies because you can annotate, photocopy, bookmark, etc. as needed. Obviously they have their limitations on access, but it really works for my workflow. I would inquire with the organization to see the format they use and limitations.