Size does matter! Zulu_Sauer's work is the go-to reference.  The following images are from Zulu_Sauer's thread found at: SHIP SIZE COMPARISON / SHIP SCALE (3.0)

5/29/13
Buccaneer added at 14.6m per the scale of the model.

6/18/15
- Added Vanduul Void
- Fixed Vanguard spelling