I think he was found to be on hormones and was banned for a year or so. Kind of explains his magical transformation from a welter into a cruiser/heavy.
Jones is now 1-1-2 in title fights. I wouldn't get too excited about his heavyweight bout though he knocked out Jeremy Bates who is nothing special as a fighter.
He's not an attractive fighter, he's dangerous but seems to have stamina issues. He gave Steve Cunningham a tough fight and knocked out some decent cruiserweights. BUT - Jones burned bridges with TV, pulling out of Showtime date sick for planned rematch with Cunningham. He seems unreliable, so that makes him a problem with TV. And he's very awkward, so not many fighters want to take him on.
Guillermo is a ****in beast in the ring. I love watching the guy fight, he is always exciting and does a lot of things in there. He fights well on the inside or the outside, switches southpaw to orthodox, and throws every punch in the book. He just needs to get in the ring more often. Yeah but all those losses and draws in title fights are controversial and close. Other than the one KO loss he has early in his career which he avenged in the next fight, he has never been beaten decisively.
It is amazing to me how he fought at such a low weight early in his career. Maybe once he started getting paid more money he was able to eat properly. I wasn't putting his title record down. He finally won one at the higher weight and like you said all of his title fights were close but I still don't see him beating Wlad or Vitali. He'd have a good shot against Valuev. Not sure what his chances would be against Haye. As far as heavyweight though he did demolish Bates but Bates is a journeymen.
The 1st rd of that Braithwaite fight was one of the most brutal openings to a match. He had him ready to go right away.
Don King ALWAYS has his fighters sitting and doing nothing for long stretches. It's pretty annoying. I'd love to see a Jones-Cunningham rematch, since they're both DKP fighters. To answer the original question, Jones is one of those guys who just moves like a boxer, and he packs a big punch, so he's a tough combination to beat. That said, his workrate is on the low side and he's kind of lazy, so he never really reached his potential.
Does anyone know where i can find Jones' fights against Braithwaite and Cunningham? Can't find them anywhere.