just to pay your attention for good thermal pads with 3 W/m-K, better than any silicone glue for good price
This does not offer higher conductivity than any silicon glue, but (assuming the specs are correct) better than most certainly.
That said, thickness is exactly as important as conductivity. And you can’t use this to get really thin bonds. In effect, a good thermal glue will outclass this pad regardless of how thin it is (thickness is unspecified).
silicon glue have 0,9 - 1 W/m-K, this have 3 so this is 3x better.
thermal glues (alumina ceamic ad silver are discontinuted) not have more than 1,5 (fisher, phobya…) so this is 2x better
for tape this is good thermal conductivity, from led supply have only 2W/m-K
( HexaTherm Tape - Thermally Conductive Double-Side Tape )
There are many conductive glues over 5W/mK as well as non-conductive over 2W/mK.
With glue you can be bond to be 0.1 mm thick while with pads are typically 0.5 mm or thicker.
oh, please show me glue over 5W/mK, i will buy asap 
The best I know:
http://www.namics.co.jp/e/product/unimec05.html
have you any store link ?
Nope. This is industrial compound, like most competitors really. You may contact the maker.
If you want to just click “buy”, this may be better:
https://www.atomadhesives.com/2-Component-Epoxy-Adhesive-Polymers/AA-DUCT-902-Silver-Filled-Electrically-Conductive-Epoxy-Adhesive
Though honestly I have some reservations about whether their specs are correct - because it looks a bit too good to be real.
Some weeks ago I made a cheatsheet with a number of interesting glues, but my computer crashed and I lost it. 
this epoxy is Btu thermal marked instead W/mK.
100 Btu in. / ft.² hour °F is 14.4 W/mk
From my point of view it would be interesting to know the Shore-value of the first material.
By the way I also prefer pads instead of glue or other creamy materials - under pressure they are much better controlable…
Bergquist has realy good materials…
Indeed. That’s far from the best, but nevertheless extraordinary. From memory, I’ve seen 2-3 companies offering something better. Of like 20-30 that I checked. Neither had a public store. I doubt any was reasonable affordable. IIRC none was room-temp curable. Also, it really stands out of other glues from that manufacturer in thermal conductivity, but not in price.
So really, I don’t have anything against them, just a hunch that something may be wrong.
A little question for you thermal pad connoisseurs: found a small thermal pad patch set as junction between a Samsung Galaxy S8's middle frame heatpipe and its CPU (I guess). It is thin, but since I've heard the S8 runs hot under heavy load (to the point of throttling down the CPUs) I am wondering if I could do a nice favour to the smartphone owner by removing the thermal pad and replacing it with some thermal paste plus maybe a 0.1mm copper shim. I believe this should provide benefit to the average SoC temperature, doesn't it? 
Cheers ^:)
Why is there a pad? Is it to reduce costs by allowing wider heatsink manufacturing tolerances or to account for thermal expansion?
I wouldn’t try to do the owner a favour without knowing the answer to that question.
Good question Agro, don't really know. Tolerances are pretty tight already and the SoC can reach toasty level before throttling events. Since her owner doesn't moans about this, I guess I shouldn't fix what it ain't broken. 
Cheers :-)
Pads are just easier to apply in the manufacturing process, are cheaper, and allow for large gaps between the two surfaces (especially good for stuff like PCBs with components of different heights)
If you use non-conductive thermal paste like MX-4 then you can definitely replace it for a performance improvement.