https://www.youtube.com/watch?v=0WssvDwtWNo&feature=youtube_gdata_player
we bought a prusa Mendel from oranage knob / romscraj... And are working through the bluid...it was only ~600 EUR, but is very easy to build and u learn a lot. The Wades extruder is a bit iffy,we may buy the machined one (extruder)from makeshop.
Stiffness seems to be key and the PM design is about 2yrs old. You do learn a lot, and it is very well supported, but I may get the back board and acryllic components for the Mendel 90...and use the romscraj parts. The ultimaker is pretty cool, and works well, but based in the PM experience, if I had the time/ money I would probably go for a aluminium frame multi- head ...rep rich has some good videos!
Again, well done Shane we r only 70% through our build, it is hard yards, but the best Lego set I have ever had!