i don't know how kind of sopngy feeling  you like. that much,
But I do own a SS 7G, its spongy feeling is heavier than the red switch Leopold I have,

And this new keyboard i got from Taobao, very old, which made in 1988. It just felt very very .... how to say.....
it's like a lighter version of the red Mx Switches, but actually you can type it further down each type.
I think I can call it a "2 actuation level" the first level of actuation is around 1~2 mm, its extremely light,
feel lighter than Mx Red switch, and the 2nd level, if you bottom out the key,
the lower part of the key are actually heavier, quite similar to Mx Black switch the lower part to the bottom.....

so now that I type without bottom out every key, it made me type easier, and almost effortless.
the sound are not as loud as red or black switches.

  every one should try it!