Book every time for me
as I hate reading stuff off a computer screen
Have things changed significantly since 2005/6? Well my Thom books are 2003 issue and there are some differences now - a few spring to mind:
Air law: low flying rules, airspace allocation
Met: new style charts
Comms: ATSOCAS changes.
I'm sure there are more. So long as you are aware of what's changed, the 2005/6 material should be ok.
Oh, and use the confuser