Essentially, the larger the barrel size the larger the curls, nothing new there then! I have been caught out by curls that fall way too quickly in the past which was due to picking an unsuitable barrel size. Smaller curls stay intact longer and larger curls will provide volume to thin looking hair but they fall faster.
Of course these days you will find curling wands* that are thicker at the base and thinner at the end. This allows you to create most of these styles without the need to have separate styling tools for each look.