Blum offers two kinds of kitchen cabinet leg levelers: one that screws on and one that press-fits into a hole drilled in the cab floor. Which one have you had the most success with? Is there another brand that you prefer (Rockler sells a version)? Why?

Here is the link to the Blum levelers:
http://www.blum.com/popup/brochure_p...ng=en&pmod=pdf