I was using 16's for sparring and bag work. I got them nicely worn in and noticed the bag work was starting to wear them a bit so i just use them for sparring and a pair of 12's for bag work. My 16's are fairly solid too i even managed to bruise a knuckle sparring with them. It was already sore a few weeks before but thought it was ok. As others have mentioned different makes of gloves have different characteristics. The Mexican ones are usually known to be harder and a 'punchers' gloves. But it's one of those things where you will probably get different answers from different people depending on their personal slant on gloves and glove makes and sizes.