Based on our record, Duplicator Pro seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
2, The logical way would be to develop the site on a staging/ dev server then move it to their live site when ready. A few things, again, need to be considered, but, for a straightforward swap, you can use a plugin like Duplicator Pro to 'duplicate' your updated version and overwrite the live site when ready. Source: over 2 years ago
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