I have spd's and borrowed a friend's speedplays (stainless steel ones) to try out. I fell in love with them in minutes. I didn't have that 'skating on ice' effect, although I can see how it would effect some people. I rode around on them for half an hour and became very comfortable with them.
I weighed my spd's and both pedals were 330g, the speedplays were 190g. I then weighed my shoe with cleat and it was only 10g lighter than the same shoe with speedplay cleat. But weight aside, the speedplays just felt better and I plan to get a pair when I replace my spd's.