I've made a bench similar to FWW's "Simple, Sturdy Workbench" (seen here: http://images.taunton.com/downloads/GSIW_workbench.pdf) which uses tabletop fasteners or S-Clips. My base is Kiln Dried Doug Fir and the top is 2-3/4" laminated maple top.

My questions is how tightly should I secure the top to the base. My original thinking was to only firmly tighten the clips at the front edge and leave the sides and rear only partially engaged and hand tight. The problem I'm having is the top slips a bit on the base now.

One thought I had was to secure the top to the front apron positively and only allow the sides and rear to float.

Heres the bench so far. Twin screw front and tail vises will come later.
2011-04-16_19-09-48_133 (Medium).jpg