It does not give more vertical since the polarisation now is in the angle of the part that goes up. So it is less vertical so to speak, for optimal reception hold your trany in the same angle. The vert. wanted pol. is just the straight hight to the top of the antenna.

The advantage is that you have a quarter wavelength antenna which gives a better match. In a T the top horizontal length only counts for 50%.
The 7 antenna gives much more unwanted horizontl polarisation since the anti phase doe s not apply as in a T.