A long time ago in a land far away, someone developed the universal needle. It was not really sharp like those old fashioned sharp needles. It was not really rounded like those formerly new-fangled ball point needles. The universal needle would sew anything. Anything at all. Woven fabric, knit fabric, stretch fabric. Anything.
And it did. Except that it didn't do quite as good a job as a sharp needle on finely or tightly woven fabric. And it didn't do quite as good a job as a ball point needle on fine knits.
Once I learned that sewing machine needles actually wear out by blamming themselves against the fabric at 100 miles per hour, I started to rethink my approach. I could change the needle before it broke. (What a shock! Sometimes back in the previous millennium, my needles lasted a long, long, long time before they broke. They probably lasted years, and I sewed nearly every day.) I found out I could hear the difference as the right needle went through the cloth. I started to get picky. And then JoAnn's started having periodic sales with 50% off the notions wall. It was downhill from there. I became a sewing machine needle snob.
The reason I wanted to use a universal needle for the project in the previous post was to make it easier to put the woven zipper in the knit fabric. Plus the only ball point needles I had were 9s. I needed a heavier needle with the Windbloc barrier between the two layers of fleece.
NOTE: If a universal needle works for you, go for it. They usually do a good job. As a point of information, I usually use quilting needles on my machine, unless there's a specific need for something else. I also use topstitching needles, embroidery needles, microtex needles, needles for metal thread, and twin needles. I have never used a wing needle or a leather needle. I'm not proud to be a needle snob, but I've sewn through my fingers enough that I won't apologize.