you can use the shield to good effect on domination in particular, I can use it and end up in positive K/D and a load of points as i can get the positions. people don't use the shield right they think that you have to have the shield out all the time, the idea is to use it when you need it e.g. when you get pinned down or capturing a position.
One tip if you are using the standard setup, swap out the 2 guns for the first one you find as they are rubbish! then you have a regular class but with a mobile hiding spot!
One of the things i like about it is that when the shield is on your back it stops bullets so you only have to then worry about straight ahead, to the left / right, windows and rooftops piece of cake
not too sure what the point of the holographic sight when you have a red dot? i have had it on and thought i may as well use the red dot.