Vance supposedly knew she had a laptop although that wasn't publicized. Well, he may be stupid, but every moron knows there is barely a middle class house without a laptop, so it is hardly incriminating knowledge.
The confessions don't help at all, they just have too many fundamentals incorrect. If you rape and bludgeon someone to death, it seems like you'd know whether they were naked at the time. At least from what's been reported, if I was on the jury Vance's statements wouldn't help me to decide guilt. But then I believe in the presumption of innocence, so I wouldn't be on the jury in the first place.
The extra DNA on her underpants really bothers me. There should have been a very limited number of people handling them, and LE could have identified who the DNA belonged to, but didn't.
Then there is this from the article you linked above:
"From day one, Little Rock police had powerful evidence in Pressly's case. She had fought her attacker and detectives recovered DNA from sperm, blood and his skin, taken from beneath Pressly's fingernails. "
But the testimony was that the DNA under her fingernails wasn't a match for Vance, neither was the sperm. Not only that, they apparently didn't even check her nails until after she died, four days after the attack. If Vance had a real defense underway, he might be able to get to reasonable doubt. If he did do it, we can all be grateful his lawyers aren't asking some painfully obvious questions.
I'm not thinking in terms of vast conspiracy, maybe just one accomplice. I have no idea why Vance wouldn't have turned on that person by now, but I don't understand anything he does.
As for the witnesses who said they saw Vance creeping around the neighborhood, why haven't they been called? Where is the gas station tape? Where is the video from the gym we heard so much about? There are two gyms close to her house, I never was clear which one made the recording, if the tape existed.
Finally, they tried the Marianna rape case in the Pressly trial. There doesn't seem to be much doubt that Vance is guilty of that one, but he wasn't tried and convicted for it. Why not?