I have never trained with Erik Paulson, but it is on my list for someday.  I have only heard great things about him from some people I really respect.  In this clip he shows a few ways to defeat the lockdown made popular by Eddie Bravo.  Very cool counters.

I have always thought Eddie was one of the best instructors around.  He has taken the time to create a system and explains it very, very well.  Here is a really cool clip of him explaining the entry to the what Matt Thornton calls "Pit Stop Position".  Great stuff!  This is about the only way I ever hit armbars from the guard.