We still use the suit. It is there to keep you alive in the event of a loss of cabin pressure. The suit is at ambient pressure until cabin alt surpasses ~35,000' (meaning below that, the suit is at whatever alt the cockpit is at). At >~35K, the suit controller restricts/shuts down outflow and the suit "inflates" (keeps suit at 35K while you get the jet in a descent). Before CARE we flew around at 27-29,000' cabin alt. Make sense?
Edit:
BTW, there's a face seal in the helmet that allows you to breath 100% O2 at the physiological equivalent of 2000'.