Earlier this year, NXT's first big show outside of Florida, which was held somewhere in California if I'm not mistaken, was in a venue that seated around 5,000 and they sold out. While most NXT shows have been in small venues, they've never had problems selling out those that hold 2,000, 3,000 or 4,000 people so I don't think the Barclays Theater will be any real problem. NXT is ultimately becoming more than simply WWE's developmental territory, it's become sort of Alternative WWE with its own brand recognition.
If the NXT special turns out to be a better show than SummerSlam or Raw, it wouldn't be the first time NXT has outshined a main roster ppv or TV taping. During the big venue show in California I mentioned earlier, Vince was backstage and was said to have really, really enjoyed the show overall. However, it was noted that he became visibly upset at the "Better than Raw" and "Better than 'Mania" chants that the crowd was into; he didn't have a hissy fit or anything, but it certainly brought his ego temporarily down several notches. I'm of the opinion that the major difference in NXT and the main roster revolves around booking philosophies and strategies as nothing that's happening in NXT can't be reproduced on the main roster. Ever hear of the old adage "what's old is new again"? Triple H is using generally old fashioned booking philosophies that rely on simple logic, consistency and paying attention to all the various little details. A small example of this was last night during Ryback's match with Mark Henry on SmackDown; while it was a pretty decent match, all things considered, the commentators spent a lot of time trying to talk up the hype of whether or not Ryback could deliver Shell Shocked to Mark Henry and later Big Show at Battleground. That's all well and good but the problem is that fans already know Ryback can because we've seen him do it; he's had matches against Mark Henry in the past where he's delivered the move and he delivered the move to Big Show on Raw during the MizTV segment a few weeks back. If Vince wants to build up some sort of suspense as to whether or not Ryback can deliver his finisher to a 400+ pound man, then wouldn't it make sense to not have him delivering said finisher to said 400+ pound man already? It's almost as if Vince believes that every fan has the attention span and memory capacity approaching that of the average goldfish while fans are given a little more credit by NXT.
