[T.G]

The various vitolas in the line all smoke differently than each other, some more noticeably than others. Like the Super Belicoso is going to be a rather different experience than the #4 (corona), yet the #4 and #5 (petite corona) are rather similar, but still subtly different.

What one person's reasons for liking one size over the other might not be the same for you.

My recommendation would be to try and get your hands on a few different vitolas; a small and narrow ring gauge, a larger one and one in between if you can. Doesn't really matter which ones, just that they are different - then see which ones you like and then explore the other similarly sized Opus X vitolas in that range.