Would rippers do well against chaos warriors and chaos Knights? I've never tried it but would the killing blow and tons of attacks make them good at taking out such elite units?
In my opinion rippers would do very poorly against Chaos Warriors of Knights. Rippers are a glass hammer and as such they need to be able to strike first and destroy/diminish a target before the target can attack back. Chaos Warriors/Knights have a better initiative than ripppers. They will chew through your unit before you have a chance to inflict any significant amount of damage. Additionally, in that match up there is too much reliance being placed on killing blow. Aside from the killing blow strikes you will have difficulty inflicting casualties against the WS, T & armour of knights and the WS, T and bodies of Warriors.
Chaos Warriors have better initiative than practically everything that doesn't have Always Strikes First, which is what makes them so OP. Saurus Warriors have about the same profile but they're not OP because they have Initiative 1, and as a result weaker enemies at least get to attack first before they are annihilated. If I had a WoC army I would do mostly Marauders to actually give my opponent a chance and just have a couple of units of Warriors as elite units. Chaos Warriors should be Special choices at any rate because they're so ridiculous.
Trust me that Warriors are pretty tame in contrast to some the other options in the WoC book. Remember that they are still only M4 infantry. Or break out the cowboys!
Not very encouraging for my M3 Dwarfs... Although I have a new weapon for use against Chaos - Slayers!!!!!!
Movement 3 isn't such an issue when you can force the enemy to come to you by blasting the smithereens out of them from a distance.
True, seeing as my organ gun gets 2 artillery dice worth of shots now rather than 1 - my close combat Dwarfs will also get a 5+ parry save if they are charged and Hatred if I roll a 5 or 6 on the Ancestral Grudge table, so maybe it's more worth it if I just sit my chaps back as a shieldwall...