Alan,
I do 'use' the rotary feature on my vise.
Once you take the time to learn how to do this, and it is not complicated or difficult, you will build better flies faster. It makes fly tying easier, especially if the quality of the finished product is important to you.
However, if you don't have the rotary feature, you can't ever use it.
If you have the rotary feature and decide you don't want to use it, you can still use the vise and not rotate it.
Put another way: there are things that you can do with a rotary vise that you can't ever achieve with a non rotary vise. There is nothing you can do on a non rotary vise that you can't do on a rotary vise.
Up to you. I doubt I'd ever want to tie on a non rotary vise again.
Buddy
It Just Doesn't Matter....