I am testing saintflint extruder,and its great!
It has sooo much power,and its perfect fit to e3d hotend.
Next step would be bondtech or printrbot geared ext,but i only support open source so this will be ok for now 
Pretty sure the printrbot is open source to some degree.
In my eyes,its same as makerbot. Published files are for old machines,or only partional. There are no complete drawings for new models,or crawlbot. Respekt to lulzbot.
@Kristijan_kolak the files as far as I know are scheduled to be released. Things such as their hotends are not open source but I really don’t see a huge problem with that. @Brook_Drumm is all for people creating new designs off of his. He might not have all the files up now but to the best of my knowledge he intends to have them soon. I don’t want to give false info so don’t take exactly what I said to heart. He might comment in on it.
Also: printrbots gear head extruder is open source and is on their youmagine as well as the play. I don’t see where they have really dropped the ball on any of their designs. Crawl bots are literally just arriving at people’s doors so I would think they are to be released soon.
@andrew_fox it was short hand for the Open Source License that Printrbot is using which, is exactly the same as the Saintflint.
Creative Commons - Attribution - Share Alike
++ what @Griffin_Paquette said ,as far as I can tell everything Printerbot sells is also in their @YouMagine collection. What would be pretty hilarious (and/or ironic) is if @Kristijan_kolak was basing their opinion of @Printrbot on the Thiniverse collection.