Hi Paul,
Thanks for posting (esp. the stats) - very interesting. Your results are about the same as mine - i.e. "inconclusive"
! I really haven't been able to tell much difference in taste or growth between the grafted and ungrafted plants.
You did inspire me to post some photos including some grafted and ungrafted plants, but I had other things to mention besides grafting so will do a separate post.
Keep us posted - looks like your garden is just getting into the full swing of things!
Anne