I own both ships, but I really don't think these add much to the original designs. You could make the case that they can degrade the overall look. Especially the FDL, which I have always considered the best looking ship design in the game.
Will be passing on these... I did buy the Anaconda and Python kits, but over time I have ended up removing all but a few pieces on each ship. Hard to argue with the original designs when you really get down to it.
I personally think the SPIKE (Reaver) kits make more sense, since they are a radical departure from the original designs. Not just some LEGO blocks you stick here and there and which don't really work in a lot of cases with the original lines of the ship.