I did it! First SPS cake...needed to practice on one before I do this wedding cake. Everything has worked out fine so far, although I had to cut the columns because my cake was just shy of 4" tall. I filled the pans (wilton) 2/3 full with batter and they baked to the top of the pan, so I don't know what else to do to make them 4" tall.
Also, I had a hard time telling whether I got the cardboard hole on the little plastic knob, but I'm assuming I did! Maybe next time it will be easier for me to tell. Thanks to all who answered my questions...especially Leahs.
One more thing...I ordered mine from GSA and it came in good time, plus they were knowledgeable when I had questions. I cannot say I got the same service from the Oasis place.