OK, I'll step up.

1) Lanceros are said to best display the flavor profile of the wrapper because the wrapper-to-filler ratio is higher than other vitolas. So, a maduro might be maduro-ier, a Cameroon Cameroon-ier, etc. This effect may be somewhat offset by careful blending that aims to produce a consistent flavor profile across vitolas of the same marca. All in all I think it is probably true in a lot of cases, but not all.

2) Lanceros are challenging to smoke correctly. While some may see this as a downside, all the really cool guys like the challenge. There is a skill to smoking them fast enough to keep them burning and slow enough to keep them from overheating. You have to pay more attention to the cigar, which in turn means you notice more of the subtleties of flavor. And if you tend to smoke too fast, smoking lanceros will help you learn to slow down.

3) And the real reason most lancero lovers prefer that vitola? Lanceros just look so damn cool. They look like they belong on an old time riverboat, in the hand of a roguish outlaw gentleman.

My first lancero was a Los Blancos (now Blanco Cigars) 9. Still one of my favorites. My absolute favorite NC lancero is the 262 Paradigm. Rocky whipped up a run of Edge maduro lanceros that were really good, but I've only seen them once. Illusione Holy Lance is a great smoke, and available in several wrappers, which gives you the chance to see just what a wrapper brings to the flavor profile.

And of course there are some great lanceros that can't be named in this forum.