If you ordered via their website, test this - go to your order, and click on the Steam Controller item. If it leads you to an error page, that should mean you are in the Oct 16th group, since they have now removed the listing for that item. If you click it and it takes you to the Steam Controller page with the 10th November delivery date, you'll be in the later group.
It can come close, but it won't be as accurate as a kb/m if you had the most skilled player for each. That's just the way it is when you have the access to so many keys and more ways to articulate a mouse / keyboard. That certainly isn't a slant towards the controller though. It's looking like pretty much the better "jack of all trades" controller solution thus far and comparable to a mouse / keyboard in terms of accuracy. It won't be perfect though, nothing is