Ive been waiting on the NX Studio since August, but have been looking at them since early last year, but budget constraints held me up until after the NQ drivers sold out. So i totally feel you there.
But they should be arriving in port on the 13th, and get thru costoms about a week after that. So we should be seeing orders ship out by the end of the month.

"Smooth" generally means it's less clinical or detail oriented, and easy to listen to for longer periods of time without fatigue.
Usually pertains to treble.
There is also "smooth" in bass when it comes to roll off, usually meaning gradual. It may mean a few Hz in extension, depending on the tuning frequency of the box/port.
A smooth roll off usually means it doesn't have any secondary humps or peaks below the tuning frequency that may cause issues with proper sub integration.
Tho "smooth" bass in terms of tone may be perceived as a general loss of texture & tone, all else being equal.
That's my understanding at least.