I like the detailing of the inverted area. It's a nice change from the typical and obvious way most 'fleet designs simply mount it at the bottom peak of the saucer.
In this case it was as much practical as aesthetic. I needed something at the base of the saucer but I was very limited on height because of the line of fire from the photorp launchers above the deflector dish.
My only quibble has been and remains the finlets on the nacelle 'wings' - I don't know what alternative there may be, but they've always looked superfluous to me, like legs to keep the model off the table, or prevent it from tipping over...
Those "finlets" were inspired by the warp rudders on the uber-Enterprise
-D from All Good Things.
They were a requirement of the design given to me by Capt Roop
and the gang that I was not originally in favor of, but I have grown used to them on this ship to the point that it no longer looks right or correctly ballanced without them.