I wouldn't call "You Don’t Know The Half" a mixtape, it's more of a compilation album. Most of these songs are off the artists' albums. And yeah, I agree, shit is dope. J-Live killed every song he was on, Oddisee never fails, and Kenn Starr feat. Asheru & Talib Kweli "If" is fucking great.
Never peep the Super Rappin' compilation, but it has been on my radar for a while now, and I will get to it one day.