First the Boreas is a flavor monster, no doubt about that.
However, I don't know if it's a misconception, it seems a valid theory to me. Why does my Haze or Theorem taste so good compared to the same coil and juice on my Avocado without the stopper (I was having wicking issues initially with the Avocado and not having the stopper in single coil fixed it)? Why does my Avocado taste better than my Griffin again with the same coils and juice?
The coils and the wicking are of course most important. A good coil that has wicking able to keep up and stay pretty well saturated is key, and that's why I think the Boreas does so well, it wicks better than any other RTA and more build space as well. But, I do think there are other factors. I know my Diablo RTA seems to have a nicer flavor closer to my Avocado and RDAs, but it's less powerful so I don't get that "soak your mouth with juice" flavor that the Boreas puts off for me. So while the "smaller is better flavor" may not be completely right, I think there is at least some evidence that leads to that thought and maybe some truth to it.
Either way the Boreas is probably the best overall RTA I've come across. I love my Diablo for it's small size but in the end it has nothing on the Boreas. Easy and exceptionally functional wicking, huge build space, high capacity and just very well designed and machined. The only thing not positive (not even negative) about it I could say is that it's not a full 8mL of capacity, probably closer to 6mL if i had to guess, as you can't fill to the brim unless you want leaking (follow the manual and it works great). But, that's still plenty of capacity