Naka seems to be an average hole-in-the-wall style sushi place. You won't find anything amazing, and you won't find anything particularly wrong, either. I didn't find anything unique on the menu... it's a pretty standard run of the Las Vegas "funny roll names" you find everywhere, with a few chef's specials.
The all-you-can-eat and lunch specials are reasonably priced. It's supposed to be $21.95 for AYCE dinner, but somehow the check graduated to $27+.
Since my last review, I would say the wait staff has been getting worse. They are inattentive and seem grouchy about taking the AYCE orders... in fact, our table had to kind of flag them down aggressively.