Users generally like the ConvertKit WordPress plugin for its seamless integration with WordPress, easy setup, and user-friendly interface. It greatly aids in email marketing, creating landing pages, managing email lists, and automating responses. Users appreciate the built-in templates, generous features even on the free tier, and excellent customer support. ConvertKit offers valuable training, webinars, and a supportive community. However, some users criticize the need for a subscription, occasional caching issues, the lack of certain customization options without CSS knowledge, and a few concerns about outdated code and plugin performance for the price paid. In summary, ConvertKit is highly effective but could improve on ease of form customization and native integrations.