YES! Hofburg has the most impressive Belmont pedigree, being the son of Tapit (3 of 4 last Belmont winners have been Tapit sons) and the out of a mare that is sired by a Belmont winner. That being said, I feel people often look at the pedigree too much and don't look at the horse in front of them. What Tenfold has that Hofburg does not is a massive stride, a high cruising speed and is a big horse with a big engine - if you remember Tonalist, he was the biggest horse in the race, had a massive stride, and recently it is the horse with the longest stride and highest cruising speed that wins (also see Pharoah who had a 27 foot stride). And as you point out, Tenfold is also bred for the Belmont and has an amazing trainer.
Now, here is what I don't like based on his work out: he is one of the best looking movers on the track, no doubt, neck bowed and very efficient. What I don't like is that he has a tie down, which basically restricts his head movement and is a training tool to keep his head down and bowed. This is often a sign that the horse can be unruly, is not supple to pressure and can lose form by running with his head too high and out of alignment. Tie downs are not allowed in racing, so I look to see how he does come race day, and how differently he looks from his work outs.
Again, I feel Justify is the horse to beat here, especially based on how he has looked in training, but this is definitely the best race if you are looking to beat him. I think the biggest factor will be if the track is dry - even tho he has won in the mud, I don't believe this horse is a mudder, but has rather been so good that he defied a stacked deck. Look at Bolt D'Oro, the only other horse nearly as heavy as him, and he finished an incredibly disappointing 12th in the KD; it is simple physics, as the larger you are, the more you sink down, the more your larger hooves collect weighted mud, and the more energy you are forced to expend.
And although Justify does not have any major distance horses in his immediate pedigree, it is important to remember that he is a carrier of the large heart gene and also that Ghostzapper, his Mammie's Pappie (where you are said to get distance from), was a sprint horse but also killed it at the mile and a quarter, broke the track record and showed no signs of slowing down against a phenomenal group of horses in the Breeders Cup Classic. I'm not worried about the pedigree. And as far far as the horse himself, he looks the the quintessential Belmont horse, and closely resembles some of Belmont's biggest performers in Easy Goer, Point Given, Secretariat and is trained by Baffert, who yielded two monster Belmonts in PG and American Pharoah.
I'm thinking possibly Justify, Tenfold and Hofburg. Vino Rosso should also be interesting, as he too has the pedigree to run here and succeed, not to mention that I think he is the second best horse in this race after Justify, and certainly the second most proven. I also keep hearing about Blended Citizen being a great exotic and having just rendered a commanding win @ Peter Pan, but to me, he just lacks the pedigree for this distance, but I'm going to do some more research on him.