I've never played a CCG, and this is my first LCG, unless you count Dominion, which I don't. That said, maybe my wife and are a little inexperienced and therefore things are working out for us differently than with others.

My experience is some races may take a few games to understand how to use their powers, but after that, they are equal. And though it is important for the KZ zone with Chaos, you still need to get your QZ going to make sure you are drawing cards and getting the good ones you'll need to be successful.

Also, I just played my wife, she built a deck out of order cards and played Dwarf Capital, I played Destruction w/ Orc Capital. I was able to win, and I must say I was very impressed with Orc/Chaos together, and even the Dark Elves helped a little. I was able to win the game, Pillage took out her KZ early by taking out a support card. Forgot the name of the card, it's the neutral one that gains a hammer for each development in the same zone. But other than the Orc Pillage card, which was important, most of the others I ended up using were Chaos.

What it boils down to is finding a faction, in any game, that resonates with your own play style. After enough games with other houses you can find the play style that works best for them, but if it is diametrically opposed to yours (say it is control when you are a aggro player) you are always going to be a little bit off your game.

Aftger talking to a lot of the people who thought Chaos was fragile it appears that a lot of them were not as familiar with the style of control and delayed rush that Chaos specializes in. They really are about disruption of your opponents plans (both offensively and defensively) as opposed to just straight aggro or straight control, or de3fensive builds, etc. If you try and play Chaos in one of these other fashions you will have less success (at least with the current card pool) than you would with one of the races that is better suited to this style.

Chaos in the Core Set is representative of the more mainstay Chaos Horde units, and touch on all 4 of the major gods dominions. I imagine at some point there will be enough cards to build a deck that is very robust with a lot of tenacity and the ability to rush, focusing on the cards that are more aligned with Khorne, but as of right now, that isn't really possible without splashing in a healthy amount of Orc cards.

my 1st ever game of Warhammer Invasion was Core Chaos v Core Orcs
and i ended up winning with Core Chaos...
i like Chaos.. they are a little on the fragile side... but i think they have enough tricks to balance that out....