The Vandas are putting up a nice display right now and I took the tape measure to the Sansai Blues! The spikes on both are now fully matured.
The blooms on my Sansai Blue from Natts ( darker blue) measures 5 inches across, the one on the Acker's Pride ( lighter blue) is 3 inches.
one of 2 full spikes on the Natts plant:
the direct comparison
and Vanda David Gardner