The Boxxer with the Stage 4 is a full-on race fork, small bump was claimed to be better than the stock RockShox cartridge, but I didn't notice a difference...
The Marzocchi is the Toyota truck of downhill forks, built to run day in day out, in any condition, on any trail... It'll take whatever you throw at it, plus in my experience nothing beats the after sale service with Marzocchi. I freaking love my 888, its a tad heavy but Ill take heavy and reliable over light and shit feeling anyday of the week.