I've played SuperSilvers once on a friend's DB. I was playing acoustically, not plugged in, and this was when my DB was pretty new to me. The SuperSilvers seemed to be very slightly louder or boomier than the SilverSlaps E and A that I use on my DB, but pretty much the same tone and touch qualities. To be fair, it's hard to say whether the volume difference was simply a difference in basses and/or venue and/or setup and/or technique rather than a difference in strings.
I remember I wondered if they were SilverSlaps while playing them before I knew what they were. I personally prefer lower tension so I'm sticking with the SilverSlaps EA / SBW Deluxe DG mix that I use, but the SuperSilvers felt like only slightly different gauges and probably only slightly higher tension, and they seemed like a very nice set.
SilverSlaps are described in
Gollihur's GHS/Innovation String section as "SuperSilver Light" strings, which corresponds to what I felt with the E and A from a texture, stiffness and tone standpoint -- the SuperSilver E and A felt to me like only a very slightly higher tension SilverSlaps E and A strings. They also look very much like SilverSlaps, only the E and A look very slightly thicker.
For reference, Gollihur measures SilverSlaps gauges at G=.088, D=.095, A=.105, E=.125 and SuperSilvers gauges at G=.086, D=.093, A=106, E=.126, so the general gauge difference is that SilverSlaps are very slightly thicker in the D and G and SuperSilver are very slightly thicker in the E and A.
That's really not much to differentiate while playing. It strikes me that unless a person is really used to one set or the other, they could probably be playing either set and not know which set they are playing.
Edit: Specifically about the SuperSilver E and A "How are they to slap?"... They felt and sounded good to me, pretty much what I was used to with my SilverSlaps E and A. As mentioned earlier, I wondered if they were SilverSlaps.