I'm using these in a Sadowsky MV5. Sadowsky basses ship with the stainless steel version of these. I very much liked the steels, but they were really bright.
I actually had them on the bass for 6 months and they still hadn't died.
The reason I switched was because I wanted something mellower and less aggressive, with a softer touch.
The Nickels offer just that. They're rounds alright, plenty of clarity and bite. But they seem more responsive to use of the VTC (passive tone control) and are, for me, more versatile and workable. They also have a smoother feel.
I've tried other brands, but I like a tapered B, and the Sadowsky just sound right.
I'd suggest these for anyone that likes rounds, but doesn't want such an aggressive sound. With the tone control these will take you from old skool thump, to bright and modern.
Tension wise, they're about medium, very comfortable.