You might not be dreaming, but it isn't surprising that producers tend to like the taste of their own syrup best. First of all, all the work involved makes you relish it, and secondly, it is a taste you've become quite accustomed to. People tend to like flavors they become used to (more on that below).
There have been a couple of studies on species differences. One was in Ontario in the mid-1960s. They compared sap and syrup of five maple species (silver, red, Manitoba, Norway and sugar). A large number of factors affected sugar content, including species, although there was a huge amount of variation. Sometimes the softer maples could be higher than the sugars....all depended upon the circumstances. The important factors associated with high sap sugar content were tree dominance and faster growing trees on good soils with good soil moisture. Thinning was definitely associated with higher sap sugar content.
In terms of taste, they prepared syrup from sap of each of these species and did flavor comparisons with 50 judges. They also included artificial (table) syrup. Interestingly, many of the judges preferred the table syrup (so it is clear that the judges were probably not maple producers, and many probably were used to, and thus preferred the table syrup taste). None of the maple syrup produced from any species was deemed objectionable. Norway maple came out just slightly ahead of the others followed by sugar maple. Silver maple came in last. Red maple syrup was in the middle of the pack.