I think the answer may depend on what you do. I’ve never used Klayvio in any business. I’ve used MailChimp and they do a good job. If I were in the E-commerce space, as you are Paul, I’d be inclined to use Klayvio if the cost of their service is reasonable, because they’re so focused on providing solutions tailored to the Ecommerce space.
Klayvio clearly positions itself in the “Text and Email Marketing for Ecommerce” as “The ultimate marketing platform for ecommerce”. They say, “Klaviyo plugs into top ecommerce platforms like Shopify, Magento, BigCommerce, and more in just a few clicks. With over 200 native integrations, it’s easy to pull in unlimited data from the software you use most, and custom integrations offer even more flexibility.”