This could definitely be considered a general LEGO discussion, but I'm talking specifically in terms of Bionicle. Which system do you like better? I like the pistons-and-gears look of the old pieces, but CCBS is really great and provides a more universal building choice. Sometimes I like to use 'old school' pieces on my MOCs, but generally I prefer CCBS. Have fun and take the nostalgia goggles off if you can.