The Mega Dolly Llama is a deadly pattern for both kings and silvers. With that being said, the Mega is a 1/2" longer and uses the largest conehead produced. This means that it is harder to cast and can be a arm/should destroyer after long fishing sessions. We recommend sticking with the #2 for silvers unless you need the added weight for getting the fly deeper.
We hope that this is insightful.
-Alaska Fly Fishing Goods