The idea is not to get the speakers off the floor, but to isolate them and keep the sound from "leaking" into the floor and adding unwanted resonances, plus anchoring the speakers so the sound at high volume does not cause slight movement of the cabinets, blurring the sound slightly.
This might be a factor with tall skinny speakers, but La Scalas have enough weight and a large enough footprint that they are very stable, making spikes not really necessary.
The floor itself may be a factor, if the speakers' feet are located between joists, allowing the floor to move in response to the music. If that's happening, you might need to move the speakers a bit, so they're sitting on the least flexible parts of the floor.
Rather than drilling holes in your cabinets, if you really want to try spikes, you can get brass spikes that attach with peel-and-stick adhesive. If you like the effect, you can leave them on, and if you don't, you can remove them, with no damage or new holes in your speakers.
Another way to isolate them is to obtain small boxes or dishes and put a half-inch to an inch of sand in them, so the feet are sitting in the sand. This is sometimes done with turntables, and could also work well with speakers.