Why would you choose WP platform over Wix??

I have a web designer who is building a web site for me and is giving me the option of using either Wix or WP. I am leaning toward WP for a number of reason but am interested in knowing which you would choose and why. Of course, I assume you choose WP but I am looking for validation of my hunches.

Also, can you recommend a very versatile, well designed and beautiful WP theme to use for my site that is updated regularly.

Thank you!