Should I use Speaker Spike / Isolation Base or Something?

It all depends on the floor and the speakers. There is a setup man who wrote a great article on why he never uses spikes and why. I had Quad speakers and adding spikes turned them into unlistenable, my current open baffle speakers sound soooo much better with no spikes and just using the feet that the spikes screw into on each speaker. Yes, with spikes it does sound clear and clean, but the body, weight, dynamics are reduced, vocals airy but no chest of weight to it. So much is generalized and becomes something you just do, I have learned over 30 years to think outside the box and try something and see how it works in your system, and #1 your room acoustics impacts more than any power cable, interconnects or a gear change, room focus to me must be #1, spikes, no spikes try it for yourself and listen. My. Dynaudio Confidence 5 speakers sound good with spikes so there you go.

You want to couple the speakers to the floor.
IsoAcoistics will decouple as will any soft things like springs.
For a night and day improvement go with Stillpoints Ultra Minis. They screw into the speaker.
They will couple and turn the vibration to heat. But the movement of the drivers will stay in the box and not be drained into the floor.
You will need 6 x $100. They will be $25 less each since you don’t need the bases. I have them on my 190 lb speakers and the effect is transformative. The best $600 you can spend.

@clearthinker,I used the Triton Refs floor spikes and went with the GAIA II instead as I felt they were a bigger improvement.  The GAIA carpet spikes are cups with metal protruding to grab the rugs, they are not spikes persay.  The footers sit inside the cups which grab the carpet.

Another vote for the IsoAcoustic Gaias. Marten loudspeakers have teamed up with IsoAcoustics for their higher end models.

@stereo5
Your speaker will still be wiggling around and muddying the transmission of your sound.
Blowing in the wind.

@miglik   Your speakers too will be blowing in the wind if you don't couple them to something solid.

The issue is to prevent the speakers oscillating relative to your ears in the listening seat.  That oscillation will oscillate the sound you hear.
Simple physics.

Try not to listen too much to MC.