Sikorsky did n H-60 with turbines, it was called the H-54 Tarhe, or the S-64 Skycrane. The S-60 was an experimental demonstrator that "sold" the Skycrane to the US Army!
It was Igor's dream, and it worked well. Also, the same rotor technology was used on the CH-53A.
The S-60 was the technology leader for the entire generation of large Sikorsky helos in the 60's and 70's.