I consider Tony Moore coming back in as a new "milestone", and then him leaving again and the new one with Todd another "start (even with the name change to Riot V). Hell I even like Unleash the Fire more so than Tony's contribution, great stuff.
I'll second this. If we're counting huge gaps between album releases than Eyehategod's self-titled deserves mention. And fucking Godflesh's A World Lit Only By Fire.