What are you suggesting? - Nerfing the Riot Sheilds Movement speed to 50/60%. While I like the riot shield and am the one who got it added, there are no downsides to using it. This could be done by modifying the SWEP itself to change the movementspeed.
How would this change better the server? - Makes it harder to abuse running away with the riotshield. That isn't what it's for.
Are there any disadvantages of making this change to the server? If so, explain. - Not really?
Who would this change mostly benefit? - The Server.