Damn, I'm too stoned to want to write a real response but what the hell.
I can say as my third CoD maining (yes, my literal tryhard class, I can't even shoot an assault rifle anymore lol) the riot "assault" shield and going possitive with it it could seriously use a buff. I understand all aspects of the shield including what part of body at all times is being covered up by the shield.
I should also say I'm a SnD player. We're a certain breed. Especially for a shielder! Most importantly, There are a minimum of 4 rounds. Thats four times the refills for your precious tact, lethal, specials ammo, or whatever it is you probably have a small number of. 4 times the wiping clean of your view. And only 6 enemies per round leaving with you to have a good chance each encounter with the enemy is more personal and well more epic, Nothings more frustrating than playing Kill Confirmed than when you've just had an epic 30 second long fight with an enemy both your ammo is out and youre taking turns bashing and knifing each other only to have one of their teammates randomly spawn and kill you.
If you're a good player in Search you can have a vague to great idea of the positioning of your enemies at any given time. In most other games its just too random for me and isnt enjoyable.
And let me mention to you unless you are of the super mega elite, you just can't be a good player in most game modes like TD, DOM, CTF etc etc.
This can be said due to the scratching surface of the shield. After 2,3,4,5 or even just 1 encounter with an enemy can leave your vision completely F***ed! After that the shield is highly rendered useless and pretty much have to kill yourself or swith to using a gun. (but what the hell is the fun in that, I chose to use a riot shield, I mean seriously, does your sniper rifle become less effective after firing 2 or 3 times, or just stop working. It's bull crap.
I've lost my train of thought but I the buff the riot shield need in this game needs is to take out the scratching of the front of the shield when shot at. Why should my shield become less effective almost immediately without even having the guarantee of 1 kill! It's bogus.
My eyes hurt. I could go into detail my personal strategies for using the shield and how i manage to be a very k/d positive player or a true SnD team player, etc etc.