| The Fender 7150 are the pure nickel strings. I haven't done an a-b comparison between fender's plated and pure nickel, but I know I just installed some pure on my P bass, and as much as I like them, they were driving me nuts on my last practice. When I would digg-in, the sound was being cropped... not sure how to explain it, but I just wasn't getting the dynamic response I was expecting from the strings.
If you have a light touch, then they are great. If you like to get the nasty when digging in, then try something else.
That's just my experience with them. I've only played about 5 hours total on them, so take with a grain of salt... | 
