they are heavier, about 5 grams at least from what i remember. they are more elastic and dense. they are likely to absorb more shock, offering better feel. if you want more weight in the head, just add lead; no point in paying $60 for a set. i think only the Prestige Pro 600 deserves the old CAPs and would warrant the expense. wouldn't look good on the Prestige 600 (green/gray).
Head Prestige Pro 600, 367g, w/ MSV Hepta Twist 1.15 @ 26/25 kg