Late to the party, but...
I understand folks who bought 16s want 16s; that makes sense.
I think for other folks this wouldn't be that big of a deal if the padding and protection is there. I have a regular sparring partner who loves his 16oz Rival RS11V Evlolution Sparring gloves. The primary reason is because those gloves at most weight 14oz. I'm fine with him wearing these gloves, they're honestly one of my preferred gloves to be on the receiving end of. Anyways I guess for me the 16oz rule of thumb for sparring gloves is just that, a rule of thumb. 16oz UFC bricks or 12oz Winnings, 12oz Winnings all day. The arguments for the 16oz gloves is the padding and the hand speed. IMHO, if the added weight is at the wrist, you're not doing my face any favors when you hit it. Slowing down the hands is cool, so you can see the punches coming, but some guys will try to make up for the speed by exerting more force to speed up their hands, thereby punching you harder. So 50% power sparring, ends up being you're going 50% and them going 80%. I notice this most with smaller guys and beginners. 100% power sparring is a different story, but honestly how often do you go 100% power. Don't get me wrong, if I had my choice, all my sparring partners would have experience, control, and wearing 16oz Winnings; unfortunately we got guys sparring with 16oz bag gloves that bottom out, you can feel their knuckles through their gloves and think sparring is about hitting the other guy as hard as humanly possible.
From reading this thread, if the padding quality and protection is there, the weight wouldn't bother me. Being able to slip your wrapped hands into the gloves with the thing fully laced up, that kinda sucks. I'm surprised that's not the bigger issue here.