I ride the Vanguard 5.2 and the Vader 5.3.
Never tried other sizes of both boards, but I love both
I´d confirm what knotwindy wrote, generally.
The Vader in 5.3 feels really large compared to the 5.2 Vanguard. I can position myself very flexibly on the Vader (further to the front / back of the board), dependent on my actual riding situation. On the Vanguard, I can rest in almost the same position all the time. Both properties have advantages and disadvantages from my perspective. I have never experienced any control issues on the Vader at higher speeds, despite its thickness / volume and agility. Maybe because I ride small mushy waves most of the time (Northsea / Baltic Sea).
I like the surfy, floaty feel of the Vader 5.3, especially in small surf with weaker winds. The Vanguard actually feels more reassuring with more grip and drive, more suitable for higher winds.