Puppy Linux has been criticized for running all users as root and for its lack of available applications. DistroWatch reviewer Rober Storey concluded about Puppy 5.2.5 in April 2011: "A lot of people like Puppy - it's in the top 10 of the DistroWatch page-hit ranking. I enjoy Puppy too, and it's what I run exclusively on my netbook. Maybe the only thing wrong with Puppy is that users' expectations tend to exceed the developer's intentions."[32]

In a detailed review of Puppy Linux in May 2011 Howard Fosdick of OS News addressed the root user issue, "In theory this could be a problem -- but in practice it presents no downside. I've never heard of a single Puppy user suffering a problem due to this." Fosdick concluded "I like Puppy because it's the lightest Linux distro I've found that is still suitable for end users. Install it on an old P-III or P-IV computer and your family or friends will use it just as effectively for common tasks as any expensive new machine."[33]

In December 2011 Jesse Smith, writing in DistroWatch reviewed Puppy 5.3.0 Slacko Puppy. He praised its simplicity, flexibility and clear explanations, while noting the limitations of running as root. He concluded "I would also like to see an option added during the boot process which would give the user the choice of running in unprivileged mode as opposed to running as root. Always being the administrator has its advantages for convenience, but it means that the user is always one careless click away from deleting their files and one exploit away from a compromised operating system. As a live CD it's hard to beat Puppy Linux for both performance and functional software. It has minimal hardware requirements and is very flexible. It's a great distro as long as you don't push it too far out of its niche."[34]

In December 2011 Howard Fosdick reviewed the versions of Puppy Linux then available. He concluded, "Puppy's diversity and flexibility make it a great community-driven system for computer enthusiasts, hobbyists, and tinkerers. They also make for a somewhat disorderly world. You might have to read a bit to figure out which Puppy release or Puplet is for you. Puppy's online documentation is extensive but can be confusing. It's not always clear which docs pertain to which releases. Most users rely on the active, friendly forum for support." He also noted "Those of us who enjoy computers sometimes forget that many view them with disdain. What's wrong with it now? Why do I have to buy a new one every four years? Why on earth do they change the interface in every release? Can't it just work? Puppy is a great solution for these folks. It's up-to-date, free, and easy to use. And now, it supports free applications from the Ubuntu, Slackware, or Puppy repositories. Now that's user-friendly."[35]