Co-dominance(or something similar to it) is exactly what I notice when growing most hybrids. Almost all of the seeds I've grown have turned out to have co-dominant traits, only rarely do I find a seed that leans only to one of the parents.
The difference between co-dominance and incomplete dominance is often hard to guesstimate. The classic example is on this page, the flower pic on the right:
http://genetics.thetech.org/ask-a-geneticist/codominant-traits-people (good site with solid info by the way). In co-dominance they both dominate expressing part of the original trait (like red and white color, both). In case of incomplete dominance they mix, or sort of express half but again both contribute to the phenotype, so red and white becomes pink. The last one is how some folks thought every trait combined: By now we know (thanks to Mendel amongst others) it's not that simple, but in practice for traits that is still often the case.
The Pine taste/smell in my P cross so far seems straight up dominant
trait. Very strong in the chunk, and very strong in the P cross completely masking the CH's grapefruit-ish smell. Easily detectable during veg already, and also on males (stems). In the P-F2, even with limited plant count, I had a male and a female that had hints of the CH's smell again, but still a little pine. This indicates there are multiple genes at play (obviously the case for things like terpene profile).
For example if P is pine, p is grape, and assuming for the sake of making a guesstimate that it was homozygous in the parents (which I actually think is the case with at least the pine). Then my F1 was PPxpp = all Pp. My F2 was then 25% PP, 50%Pp, 25% pp. That would mean that those F2 plants smelling like CH (pp) should not have a hint of P, as that would require being Pp, which I know from F1 has not hint of grape. So that's not the case.
Now if the taste would be based on 3 genes, PQr (PP QQ rr) for pine, pqR (ppqqRR) for grape there are different combinations possible of which more than one can smell like a mix. E.g. PQ could still perhaps contribute enough to result in a pine smell, and the R enough of the grape smell. In reality there can be many more. When the underlying gene pairs are homozygous in the dominant side, the trait initially can seem complete dominant. If the underlying gene pairs include heterozygous pairs it can appear initially as incomplete or co dominance.
A more obvious example of my point, take for example a quantitative trait like height. If you cross a small plant with a large plant you get a range of plant size in the offspring. The plants will be on the spectrum between small and large. This is because height is based on many genes. This also means the environment has more influence on that trait, i.e. more phenotypical differences for quantitative traits which increases the perception of getting more variation genetically as well.
So the point is, what looks like incomplete or co dominance is often a mix of multiple underlying gene pairs. In the underlying pairs a side/allele can still dominate completely but possibly not make enough difference for the trait it contributed to dominate in the pheno expression. Dominance/recessive is technically a gene action, it only applies directly to the relationship between two alleles in a pair. So for a trait to be dominant it has to be based on a single pair else some of the pairs that make up the trait can be dominant, but others can be for example co/incomplete dom, recessive, additive, overdominant.
I hope this helps, and thanks for asking, I do enjoy rambling about the theoretic side, obviously in practice your miles will vary :)