All the information you need is over at the Naked Whiz website, but to answer a few questions...
Kingsford burns longer because its more dense than most lump. Lump temps can vary with brand, species, and size.
Some people pick up an off taste from Kingsford, particularily on long cooks (usually ascribed to nitrates). Most people will notice the natural woodsy flavor present in most lump.
Good lump is more expensive than Kingsford ( adds up on overnighters), so that must be weighed against the real or percieved "advantages" of lump.