I've had my HT2-TLs for a few years and have never installed the feet due having soft pine flooring in my listening room. I was going to buy a set Herbie's threaded stud gliders so I didn't have to worry about marking up the floor. But at close to $140 for the set I decided to take a closer look a possible ways to use the feet that came with the HT2-TLs.
I didn't realize that the provided feet are not spikes per se but are slightly rounded. I went all out on a custom application so I could use the feet
. I had a bunch of heavy cloth placemats and stacked three together for each speaker. This worked quite well and cushions the feet so the floor isn't marked and makes moving the speakers into position real easy.
I found that the HT2-TLs have a bit better bass response and imaging was improved slightly. Not sure if this is my imagination or due to better speaker/floor isolation and also raising the height of the speakers 2 1/4". The one aspect of installing the feet that surprised me is that the HT2-Ls are much more stable with the feet installed. I thought the HT2-TLs would not be as stable but they are now very stable even more so when the plinths were flat on the floor.
So I highly recommend that anyone concerned about installing feet on their Salk speakers due to flooring or other concerns to definitely do it. You might have to come up with a "custom" install as I did. But it's well worth the effort