Michael and Mike came to my friend's comedy show (he is also, coincidentally, named Mike) to show off some of their stuff back when they were first starting to get noticed. They showed an episode of "Network" ("Buidlings") and a couple bits from "The Middle Show". I thought Network was... odd... but kinda great in its own way, and thought the Middle Show was adequate for what it was. I started checking out their site (black20.com) and found that the clips I'd seen were fairly representative of their content.
Some of the stuff these guys do is extremely funny. The Middle Show is probably the most representative show. It sometimes hits, but often winds up not being that funny. Network is often great, but sometimes Mike and Michael get a little indulgent and off their own sketches, and a funny beginning will turn into a long and meandering end. I have never found Black20 News to be watchable. I'm sorry to Jessie Cantrell, but I just can't stand it. My favorite thing they ever did was their very short lived "Sheffield Quigley: Professional MySpace photographer", but I understand why they didn't do many episodes of it. I guess once the basic joke is out there, there's not much room to make it grow. But still, they invented two strong characters for it who had a great comedic relationship.
I guess that it comes down to this: these guys used to put out an awful lot of content. Some of it works, some of it doesn't. British Brothers is sort of the best thing of theirs that's up here, but it's far from their best work. I think Black20 deserves a look, if for Network and Sheffield Quigley alone. I sincerely hope they get seen by someone who can help them develop their work. Right now, if you go by the selection they've put up on Hulu, you're not going to get an idea of them at their best.