Having briefly owned the 3D20, the reason your parts are sticking too well is that you have the first layer too close (this is definitely a factor of the build surface that they provide). Move it back a little at a time until you get the amount of stick that you want.

I ended up returning mine because I felt that it was just too expensive for what I got (only PLA, no heated bed, somewhat crippled software, warranty voided by using 3rd party filaments, etc, etc...). In hindsight, I'm glad I did because the unit I bought to replace it was 200 dollars cheaper and does everything...