Tens of thousands of wireless industrial monitoring deployments exist today, logging more than 18 billion operating hours. These solutions have been around for over a decade and are based on standards such as WirelessHART and ISA100.11a to provide performance guarantees to the applications. The new trend in industry deployments is the convergence of operational and information technologies happening through the Industrial Internet of Things (IIoT) paradigm. The challenge is to bridge the performance of these well-proven industrial standards with the interoperability of IP-based systems. The Internet Engineering Task Force (IETF), the organization behind most of the technical solutions of the Internet, has produced a set of specifications with this requirement in mind. The output of this effort is the 6TiSCH protocol stack based on open standards, such as those that have played a key role in the Internet's ubiquitous adoption. The standardization of 6TiSCH is done. The state-of-the-art research work focus is on important, but niche, optimizations and performance evaluations of the 6TiSCH stack. This paper takes a different approach-it evaluates the performance of the standards-compliant 6TiSCH solution from the end user point of view. It does so on two experimental testbeds, in typical IoT test scenarios based on a well-defined experimentation methodology. We provide a set of Key Performance Indicators (KPIs) useful for the end user to decide whether the 6TiSCH technology is a good fit performance-wise for a particular use case. We demonstrate reliability of a vanilla open-source implementation of 6TiSCH above 99.99%, upstream latency on the order of a second and radio duty cycle well below 1%.