I was curious, and I suspect this topic of NC State vs Illinois is going to come up more with both jobs being open so I am throwing some info out there.
Obviously, I'm biased, and I didn't dig too deep, but I did not intentionally exclude anything anti-Illini.
ATTENDANCE
Attendance #s over the last 10 years, with Illinois then NC State in parenthesis:
2016 - 27th - 12,723 - (8th)
2015 - 15th - 14,652 - (12th)
2014 - 15th - 15,246 - (25th)
2013 - 17th - 15,013 - (12th)
2012 - 14th - 14,986 - (20th)
2011 - 10th - 15,851 - (19th)
2010 - 12th - 14,870 - (24th)
2009 - 13th - 15,499 - (21st)
2008 - 11th - 16,618 - (16th)
2007 - 10th - 16,618 - (18th)
http://www.ncaa.org/championships/statistics/ncaa-mens-basketball-attendance
Illinois averages 1,000 more fans per game over the last 10 years, and has had a 92% capacity while NC State has had a 72% capacity. I did not realize how big NC States arena is at 19,772, wow.
VIEWERSHIP
I looked for viewership statistics but couldn't find any that weren't behind a paywall. I did find numbers on the top 10 highest rated games per conference:
BIG #1 @ 3 million per game
ACC #2 @ 2.5 million per game
https://www.statista.com/statistics/290382/average-viewership-per-ncaa-basketball-conference/
PUBLIC OPINION
Here is an article written in 2013 ranking the top 25 Men's BB jobs with Illinois at #17. NC State is listed with Arkansas, Butler, Creighton, Gonzaga, Marquette, Oklahoma, Purdue, Villanova, Wisconsin, Xavier as "almost made the cut".
http://www.sportsonearth.com/article/64621444
RESULTS
Tournament Appearances All-Time
Illinois - 31 NCAA, 6 NIT
NC State - 25 NCAA, 11 NIT
Tournament Appearances Last 30 years
Illinois - 19 NCAA, 4 NIT
NC State - 13 NCAA, 6 NIT
*Note that I'm not shaping the numbers by using a 30 year mark to avoid our disastrous '70s. Illinois had no NCAA appearances during the 1970s, but we had the same number of NCAA appearances (6) from 1980 - 1986 as NC State did from 1970 - 1986. They did have 3 NITs while we had 2 during that time.
Final Fours
Illinois - 5
NC State - 3
Elite Eights
Illinois - 9
NC State - 6
Sweet Sixteens
Illinois - 11
NC State - 11
Average Conference Standing All-Time
Illinois - 4th
NC State 6th
Average Conference Standing Last 30 years
Illinois - 5th
NC State - 7th
https://en.wikipedia.org/wiki/List_of_NC_State_Wolfpack_men's_basketball_seasons
https://en.wikipedia.org/wiki/Illinois_Fighting_Illini_men's_basketball
REVENUE
Illinois - $86 million
NC State - $77 million
http://sports.usatoday.com/ncaa/finances/