Most of what i'm about to say come from just viewing the 4 trailers (have yet to watch episode 1)
When it comes to RWBY (pronounced "Ruby" if you didn't know ) you have to come into this anime as if it's something new and not base it off anything else. The reason I say this is because RWBY was created by roosterteeth (check title of post for confirmation) and if you know roosterteeth, then you know this is something new for them. Trying to watch RWBY as an anime and expecting it to be like roosterteeth/achievement hunter and you are in for a let down. RWBY is a new step for roosterteeth in animation and Monty (head animator) in showing off his animation skills. He started animation with the RvB series when they went that direction and decided he wanted to show the fan base what he could do.
Now about RWBY, Have i watched this episode? no (at least not yet because i have an exam in the AM) so i can't say much about it, but i can for anime's in general. Going by forum posts and friends statement, the hardest part about watching RWBY as an roosterteeth fan was honestly the voiceovers. Knowing who does the voice makes the anime a let down because you know how that person really is. Jack is a prime example during the Yellow trailer, You hear his voice and realize "is jack trying to sound 'hardcore' (or whatever word you want to use there i dont fucking know) ? " and moments like that can ruin the experience for you.
Now for the animation sequences, mainly the action ones. On the plus side, the animation was done really well compared to some other american animes. The animators were required to watch both japanese and american animes to understand just exactly how the animation should look/work and with RWBY that went well. Some of the action sequences were too drawn out and a overuse of animation was beginning to form within the trailers. when the Red trailer came out, it seems that the action was downplayed in order to try and focus on the characters which is what should be done. Monty was smart in letting us know small details about the characters and not reveal too much just yet. The White, Yellow, and Black trailers focused way too much on action instead of what should have been shown.
Ill finish tomorrow.....tired..zzzz