Nopee.. I always keep my cool. I do say things like, "Hey, my shield is pointed at you", or, "Hey, eat bullets". But that's just because I know the enemy can hear me.
...I love the assault shield. Seriously. It's SO much fun to use... as long as you know you're going to die a lot. But once you get the hang of it...?
Seriously, its all about situational awareness, and KNOWING your shield: ie it's flaws.
I've been in situations where I'm backed into a corner, three guys are firing at me all at once, and not one is getting a hit.
You have to know how to use it, you have to spec your class for it (x2 Stuns, x2 C4s). I run with a knife because well.. it's a hell of a lot faster than even a pistol and face it -when fighting with a shield it's always close range.
Flak Jacket is a must. Fast hands is a must. Engineer is a must. I get the majority of my kills with this class through nades - the ones they throw at me.
Just resign yourself to the fact that you'll only get MAYBE 2 kills with shield bashing per life - maximum. Your two stun sticks. It's the only way, man - unless you get someone who's simply not paying attention, or you spawn behind a camper.
Would reccomend dual perking for lightweight, if you can manage. Run with knife, dive, pull out shield, advance.
Do what me and a few of my buddies did. A phalanx of four shields, with one or two grenade launching AR guys using you as cover. - Literally won the game for us (on Nuketown, no less! Lol)
But yeah. I find it incredibly fun to walk up the stairs while being blasted at a guy from the top, only to have him retreat into a room, desperately trying to stay out of melee range of me. It's hilarious. He's got a FRICKEN MACHINE GUN. I got a hunk of metal xD'
"It's so much fun to use... as long as you know you're going to die a lot"...
That pretty much says it right there, it's broke.