Reviewers see ChatPDF as a handy way to question long PDFs, summarize dense sections, and pull specific details from research papers, contracts, and books without manual searching. They especially value its speed and the ability to get references for later fact-checking. But the feedback is mixed on reliability: some say it occasionally returns unrelated answers, fails to answer queries it handled before, and still cannot analyze multiple PDFs in one chat. One reviewer also argues the paid plan is hard to justify versus ChatGPT, though the limited free version is convenient.