which study material stalla / schweser /.... is good for L3

What are the strengths and weakness of the study materials available from different companies [Schweser / stalla / …] Who has better lectures ? who has tougher questions ? who has better study materal ?

If Stalla adds Peter Olinto choose them otherwise Schweser… Sign the petition to convince Stalla to let Peter Olinto do part of CFA L3!! http://www.petitiononline.com/StallaL3/petition.html