Maybe I define overdrive differently, but I own a Darkglass B3K and wouldn't really classify it as a OD pedal as much as a distortion pedal. If you back the gain stage way down and blend it more towards the clean tone, you will get a fat overdrive tone. Absolutely no bass suck. I just think your aren't getting your money's worth out of it by doing this.
Based on the clips I've heard online, the Pork Loin is a nice choice for simple overdrive. I'm thinking of getting one for some dirt and then using the B3K as a louder, more distorted sound when I have to fill up space during guitar solos.
I'd like to hear more about the Black Sheep as well. Interesting idea.
The Aguilar AGS circuit in the Tone Hammer DI is nice too, but it doesn't suit my needs.