The elctrogreandes are really good against droids. I remember using them int he Xbox demo. They also give organics a jolt and stuns them.
I like the sonic grenades a lot more then thermal detonators because the TD suck. Sonic grenades kill instantly, but sometimes TD will just deal damage.
I'll be running around like crazy and shooting after ordering a clone to plant the bomb, but I still get hit in like one shot :/
I also think the clone rifle is way underpowered. I takes half a clip for me to kill anything while my handblaster kills in 2-4 shots.