Using platforms / shelves under floorstanders?

I use maple platforms that are custom built by a member on this site (Monobloke) for my Gallo 3.1's and am very satisfied.

It depends what your floor is made of. If it's concrete then maple platforms might bring some improvement to the sound. I have the Mapleshade platforms, on concrete floor, and they do very well. But using them without spikes wouldn't make so much sense, I imagine, because you'd lose the coupling to the floor.
One way to prevent damaging woodfloors because of spikes is to place Yamamoto PB-10 footers under the spikes. They're imported by Venus Hi-Fi, and you'll find a review of them on 6-moon.

Check out Promethean springs at Machina Dynamica website

In my trials, I've found, that maple under the speakers pretty much kills the sound. Sistrum SP-101 is so much better. With time, I'm going to get rid of the maple in my system alltogether.

I used a sandstone slab + nordost pulsar points, but find a Symposium Svelt shelves + Rollerblock juniors, a significant improvement on a suspended wooden floor.