I have read that to much grain matter in the boil can release harsh tannins. I have many times forgotten to vorlauf and ended up with much more sediment with no effect on the taste. The only effect I think more sediment could have is trapping some of the yeast under it, which could effect fermentation, but it is doubtful.
-St. Louis Brewing Group on HBT
Fermenting- Dark Crystal ESB, Vanilla Poter, Oatmeal Cookie Ale
On Tap - American Amber, English Pale Ale, Deception Cream Stout
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