The honest version of this comparison is shorter than most: for a small business site, the free plugin does everything the design needs, and the interesting question is not what Pro adds but who pays for it in year two.
What Pro actually adds
A theme builder, a form widget, popups, a handful of dynamic-content widgets and a WooCommerce set. Everything else in the widget list has a free equivalent or a plugin that does the same job without a subscription.
The renewal problem
A client who inherits a Pro-dependent site inherits a renewal they did not choose. When it lapses, the site does not break immediately — it stops updating, and the widgets stay frozen at the version that was current when the licence ended.
How we build around it
Every Novex theme ships its header, footer and forms as theme features rather than builder features, so the layout does not depend on a licence. If you already own Pro it works alongside the theme; nothing in the design needs it.