The new ID's will beat the old Chameleons. Better xover, beter mid with more midbass potential while still maintaining the detail. They did not go to new models for no reason, they are an upgrade.
Those are two different sounding sets, the rainbows and the ID... soft-dome tweeter vs. metal for one thing. I would go with the rainbows, but that's because I like the sound of metal tweeters. Honestly, you can't go wrong with either, you could flip a coin.