I really like the visual aesthetic and the efforts you put in the default style of the main demo (not a fan of the other ones though).

That being said, I feel like many small improvements could help:
- The slider navigation arrows could be slightly bigger. I find them too small and hard to notice.
- Still concerning the slider, each slides miss a clear CTA, so that it's more obvious they lead to something
- The calendar is pretty well done, but for the "as month" view, more white space around each event, maybe the use of color, and increasing the contrast with the font-size could help the legibility. Right now, it's a bit hard to read.
- The bread crumb needs to be more noticeable

The possibilities and features of the theme are pretty cool :)

Like the consistency of the elements. Every UI element is giving that sporty feeling - the choice of typefaces, italic style, the indented cta buttons, icons, interactions.

There are also a lot of different possibilities for customizing the theme, with a lot of different features provided (forum, shop, shortcodes). Seems like, you have thought about every feature that could a regular sports center, sports shop, a trainer etc. use.

Also the documentation seems very nice with in-depth explanations. It's not really made for smaller devices, but I get that - people will in 95% use the documentation on desktops. On the other side, theme's UX on smaller devices is great.

Nice theme guys.

Features are well-packed. Love all your UI elements.

Might need to improve your choice of images in order to make your product more promising. :)