WKO5 has a free 14 day trial. Download it and try it out to see if you think you will use it.
I don’t have any experience with GC but WKO5 will not prescribe you workouts. So far, I like WKO5 way more than WKO4. I really struggled with WKO4 but I am actually liking WKO5 and I think its easier to use.
I’ve been using WKO4 from about the time it came out and just upgraded/paid for WKO5 yesterday. In WKO4 I referred to the Optimized Intervals chart and used it to some degree in forming or refining some PerfPro custom workouts in terms of intensity and duration. So not exactly like Xert, which I tried back when it first came out, but this chart can help to some degree in shaping one’s workout. I’ll admit that I am not a savvy user and don’t utilize WKO4 as well as I could.