I think the price on Simon (-230) indicates this match-up may be closer than one might expect. H2H, Simon has run over Bellucci in the past but right now, Bellucci is serving good enough that I think he'll be able to compete here. And if he does continue to serve well, a close 2-setter will cash this, although I believe he's gonna be able to win a set here against Simon. 21.5 is a relatively low total to cash the OVER unless Bellucci goes into his classic tank-mode. He's only been broken once in his last several matches, albeit against much inferior opponents, so expect Simon to have difficulty in his return games.
(-230) on Simon may also be a result of fatigue, as he has been playing alot the past several weeks...because I seriously think this line should be closer to -300, if not more, had Simon been more rested prior to this match. I also wouldn't be surprised if Simon decides to take this one easy and accept an exit here to get some rest for the Grand Slam.