I am considering buying a 2019 Canyon Denali because it’s roomier than other midsize trucks. Should I be concerned about anything? Is it a reliable GMC vehicle?
Based on complaints at NHTSA.gov and carcomplaints.com it is a fairly reliable truck. The most mentioned complaint is for the transmission but only two complaints are listed at NHTSA and four at carcomplaints. There are no recalls or investigations by NHTSA. You can check out reliability at Consumer Reports too if you have a subscription or your public library has one. According to Edmunds.com, expect repairs for the next 5 years to be about 20% higher than for a Toyota Tacoma.
IIRC there’s been some Canyon owners who have posted about a few problems they’ve had, posted here (both general discussion & maintenance categories) within past couple of years. You should be able to find those threads using the forum search feature, link upper right this page. In general you’ll have fewer problems if you minimize the number of gadgets and gizmos, and manual transmissions seem to cause fewer problems than automatics, but MT option may not be available on a Canyon.