Speaker spikes are almost always beneficial. The problem with tile or other hard surfaces is the damage the spike can do. The weight of heavy speakers, combined with their energy transmission during music sessions can literally "drill" a spot in your floor.
Sound Anchors makes stainless steel discs that employ Kevlar on the back side. Not only can these disks not be penetrated by any spike, the Kevlar does not store energy when working against rock hard surfaces such as you have.
I plan to use the Sound Anchors on my new floor, I have slate, which is hard but certainly vulnerable to the stainless steel spikes I use. For what it is worth, the Sound Anchor product was a Stereophile best buy recommended product. I think it is better to buy a few and listen first though, rather than follow only my suggestion or the magazine.
Sound Anchors makes stainless steel discs that employ Kevlar on the back side. Not only can these disks not be penetrated by any spike, the Kevlar does not store energy when working against rock hard surfaces such as you have.
I plan to use the Sound Anchors on my new floor, I have slate, which is hard but certainly vulnerable to the stainless steel spikes I use. For what it is worth, the Sound Anchor product was a Stereophile best buy recommended product. I think it is better to buy a few and listen first though, rather than follow only my suggestion or the magazine.