Wow, blacksheep998! Your experiences are almost the exact opposite of many people! I find the neocaridina species (RCS, yellow, snowball) all are much more aggressive than CBS, CRS, or others of that sort. The neocaridina will bully and outcomplete and outbreed the crystals time and time again.
My crystals seem to be weirdos in every respect. They breed like mad in water with a pH that's unstable and swings higher than 7.0 on a daily basis, and they're total bullies.
I mentioned my yellow shrimp tank crash above, when that happened I had a handful of male yellows left but no females. I didn't intend to buy any more of them so considered the colony 'dead' and moved the remainders into my crystal shrimp tank to live out their days.
The crystals abused them like you wouldn't believe. I don't think I ever saw the yellows get into the feeding frenzies. A few times I saw them try but were attacked by the CRS and chased away. Even when there was no food, I saw CRS chase the yellows a few times, it looked like when a shrimp is dying and the others start going after it, knowing it's going to be food soon. But these were healthy yellows.
There's an old video of feeding time on youtube here http://www.youtube.com/watch?v=r61KYH1J5iQ
It might not look too wild but keep in mind that was back when I only had about 25 adult CRS/CBS and maybe 100 young. Now I have well over 200 adults and probably another 200+ babies. I haven't taken any videos of them eating lately but here's a picture of what I call 'the shrimp pile'. Even in the still image you can see how much activity is going on from how much motion blur there is.
Anyway, sorry to hijack the thread. Just pointing out that there can be huge differences in behavior between colonies of shrimp, even in the same breed.