I run a Conversion Rate Optimisation Agency and would be happy to help you design a new landing page to test as part of a free consultancy, in return for a review/testimonial of our work.
As one of the other comments has already touched on. You did not actually test smiling faces vs non-smiling faces as both the landing pages are very different in more than just one element.
Also, from my experience your industry to better suited to different types of tests such as the value proposition and the selling of the benefits rather than the features of your product.
Answer the visitors need/desire and they will sign up
Let me know your Wordpress Site URL that you would like me to take a look at.
I will then perform an audit for you and identify how much I can do to help you and I can then provide you with a list of changes to make to speed up the site.... Or I can go in and do the optimisations for you if easier..
Let me know if interested.