I have the 2012 model GT3542LS but have never removed the spikes. I looked in the "instruction pamphlet" that came with it and you CAN remove the spikes. You use the included allen wrench and place it in a hole in the spike and twist it off/on. It even illustrates how to do this.
Edit: The metal spikes come pre-installed on the legs and are hidden under the also pre-installed removable rubber feet. Also included is optional "snow feet" if this is of interest to you.