I started the same tranistion a couple of years ago and whilst a looooong way from being an expert I can only echo some of the above comments:
1) Make sure you get the right unit for you. Again with the awareness robbing nature of photography I prefer a completly manual mCCR. It simply doesn t allow me to zone out.
2) Also just use common sense and build back up to full trimix with a camera
3) Never get complacent. CCR doesn t allow it.