I cannot cosign this either. You can't have the 15th ranked total defense at this point in the season without having some impressive defensive performances. Yes, the D has yielded too many big plays... but part of that is personnel related, part of it is slow adjustments by coaches, and some of it is the sheer fact that some units provide a terrible matchup for our D. Overall Tech's defense has performed well this year. Absolutely dominating in a few games, very good in a couple of others, and average to poor in two. It's statistically better than 113 other defenses out there...
Eh. If you average out our FBS opponents, they're about 60th in total offense. UNC is kind of a wash, because we played them in a monsoon. Bud has out-schemed Fedora before, so I don't think it's just the weather (still would have won going away, IMO), but it was a historic game in terms of low output for UNC and that did factor in. ECU is 13th overall, and even though they're not from a power conference, that's probably our best overall effort defensively under normal playing conditions.
My concern is more that Pitt gashed us on the ground -- going about a half yard over their average of 5 ypc, while doing serious damage through the air as well. Tennessee is by no means a spectacular offense, but their ypc against us well above their average as well and they were also extremely efficient through the air with short fields. Even Syracuse's god-awful run offense was slightly above its average. None of these statistics are necessarily alarming, taken alone, but considering our defense has given up over 450 yards on average our last 3 games, and around 30 points, it does show a trend, IMO, and I do think teams are learning to scheme better. As far as big plays, we've given up 33 20+ yards or more plays, which is about average nationally. Going further, though, we've given up 20 plays of 30 yards or more, 82nd nationally, and to me that is troubling.
The things you mention in regards to personnel and defensive adjustments can't just be waved away, because those are parts of the scheming, preparation and evaluation processes important to fielding top defenses. Our defensive recruiting has been hit-or-miss to dreadful in recent years, and it has hurt us a lot on the field -- particularly up front and with our linebackers in terms of depth and health. I think that's happening to an extent again this year as the season has worn on.
So, yeah, you are definitely right that our defense has been good, and prior to the Syracuse game I might not hesitate to call it spectacular even. But the last few games have me somewhat concerned, and I stand by my statement that they have not been particularly spectacular this year -- especially against decent offensive competition.