The MX gloves that Cotto wore were the exact same as the 2nd pair of MX gloves that Maidana chose though and were fresh out the box and approved as legal
Even then, he turned down the Reyes gloves too and nothing was wrong with those either
MX gloves and Reyes gloves all have padding distributed in a way that you can feel the boxers knuckles through them, allowing you to do a little more damage. They are punchers gloves....alot of fighters wear them including Pacquiao, Cotto, JMM, and Khan.
Hopefully Floyd lets him wear the gloves he's comfortable in and fight Maidana at his absolute best.
No point fighting an opponent who's only chance of victory is via ko.....and handicap him by making him wear bigger "sparring gloves"