I get more BTU's out of lump than kingsford. It starts up twice as fast as well. Burns much hotter. Goes out easier (when you snuff it). Produces 1/10th the amount of ash as charcoal briquettes. Only problem is the size isn't uniform like briquettes so you can get pockets of air between the lump which causes temp instability.. so you have to pack it well.
I like that kingsford blue is more popular than lump charcoal, this keeps the lump charcoal prices down.
18.5" WSM and 22.5" OTG.