I have a regular NC 28 as well as the LED model.
I swapped out the pumps in favor of Sicce Syncra Silent 0.5's, as the stock pumps are noisy and power-hungry, which makes them run a tad warm (80*F or so).
The cooling fans in the lid are also noisy and should be replaced.
Other than that, the thing I REALLY don't care for is the "bowfront effect"...AKA distortion. If you like seeing your critters, the 24 gal tanks are much better in that respect (also have a couple of them).
That being said, they make great QT/growout setups...we have 5 "plug-n-play" setups and are perfect for what we use them for.
If you want a tank that size as a DT, I'd consider getting a std 29 gal and save yourself some money, OR if the P-N-P appeals to you look into the NC 24 or a BC 24.
HTH