Which is the more significant MBP upgrade? Rev A? B? C?

[superspiffy]

Which, do you guys think, is the more significant MBP upgrade??

Rev B (Core 2 Duo) from Rev A (Core Duo) or Rev C (Santa Rosa) from Rev B (Core 2 Duo)?

 

[flopticalcube]

From a software point of view, B from A.

 

[dartzorichalcos]

Rev B. ------> Rev C.
Rev C. really had a lot of new features. Rev D. might be Penryn and might be an even bigger update.

 

[solaris]

Rev. B -> Rev. C

Since it by this update finally have features on par with the PowerBook G4 it replaced 1 1/2 years ago. I am talking about the 15"...
All these features at the same time, which all were part of the latest 15" PB:
* 8x SuperDrive
* 7200RPM hdd
* FireWire 800