Among Canon fans, the "L" series represents a pinnacle. As good as it gets. To have that red band on the lens is making a statement. "L" series lens are made for the pros, who demand the best, and need their gear to work in extreme conditions and still produce outstanding quality.
Recently, one of my friends acquired an "L" lens, the EF 100-400mm f4.5-5.6L IS (or as it is referred to around office "The Bazooka"). I was playing around with it and got this shot at the full 400mm end. The longest lens I own is a EF-S 55-250mm and the comparison of results, well, lets just say I'm hearing the call of the "L"!