Yea, Roach/Hydra ball around Kerrigan is pretty much 'roflstomp mode'. Vile Roaches make even more interesting. Maybe throw in a couple of Ultras or a vanguard of 'lings.

Normally, I go for piercer Hydras, and never bother making any. This time around, I went for Lurkers, and never bothered making any.

Never figured on doing a muta-ball, but I can see that being effective as well.

Never bothered with Vipers. There's never any situation where pulling opponents out of position is really all that useful. Broodlords are at least good at bombarding targets, even if it would be simpler to just bring in Kerrigan + hydra/roaches.

Ultralisks come late in the game, and their upgrade comes even later, making them less than useful. Which is a pity. If anything I wish for Blizzard to learn, it is this: Give me a few end-game missions where I get all the toys to play with, not just one.