Don,
Since I have never used slips, I hoped that someone else would have responded to your question. On his blog, Chris Swarz gives some benefits of slips, but having read them, I'm not sold. He states, "In some accounts, drawer slips are a mark of quality work. David Denning in The Art and Craft of Cabinet-making (Pitman, page 186) says that joiners typically grooved their drawer sides. Cabinetmakers typically used slips." If this is true, then I don't know any cabinetmakers, only joiners. As discussed in a thread elsewhere on this forum, the distinction between a joiner and a cabinetmaker doesn't appear to be the techniques used to join their work, but rather the use of veneer (cabinetmaker), and possibly semantics. Chris points out that the use of slips can avoid the need for a half tail at the bottom of each drawer side. I've always located the groove at the bottom of a full tail--about 1/2"-5/8" from the drawer bottom. I do see his point about fishing objects out of the bottom of a drawer, but this hardly seems a sufficient reason to start using slips. I wonder if it is a construct used more where softwood drawer sides may wear prematurely. The slip could provide additional bearing surface...just wondering. Anybody else have any thoughts?