The record's not terribly inconsistent with Williams' past work. If anything, it's more akin to your average hip hop record than his self-titled was. And like with a lot of slam poets, he's a lot better live than he is on record. Slam poetry does, after all, have a heavily aleatory element to it. It's just not the same on record.
That having been said, I don't like it a whole lot either. The new Little Brother, for example, is better. But I still think you're overreacting, particularly in it being worse than 50 Cent. The biggest problem is that the music (mostly unreleased stuff from The Fragile) doesn't jibe with the vocals like it optimally should. I really disliked it at first, but it's growing on me, though I'll never think it's great. It's one of those albums that would work better as an EP.
For Saul at his best, look for a Blackalicious track called "Release".