OK. I 'm gonna make myself unpopular again!
I frankly don't understand the fuss about the spice tree...Although John is definitely doing a good Job, with a lot of love for his work and also a lot of knowledge.
We had the spice tree in a blind tasting a couple of months ago, and 90% of the audience thought it was remarkebly similar to an ex-sherry cask, european oak cask. (all people with more than 10 years experience in tasting)... and yes, if you put it in a line-up of european oak matured whisky's, it does not stand out as much! (just like the 'Truffle-oak" by Glenmorrangie)
To me, "spice tree" proves what a lot of experts say: that the species of wood (ergo: european red oak, or american white oak) has as much, or more influence on the ultimate taste over the long run (meaning: as maturation vessel, instead of finishing vessel) than the previous contents of the cask.
In other words:
Finishing (= less then 2 years further maturation....just to put some arbitrary line) = more influence from the previous content
Maturing (whole maturation in same cask) = more influence from the woodtype, less from the previous content.
What do you think?