Yeah they’re pretty anemic for sure. I’ve got well over 1/4 million miles on 2012-2014 models. Put 200k on my first 12’, 120k in my second 12’, and close to 100k on my 14’ before getting my 15’ Dmax. They’re bulletproof, but they don’t move out of their own way for anything.
As far as problems I had the occasional GM electrical gremlin, but they were just annoying inconveniences. Never anything that slowed me down. I’ve had 3 15’ model Silverado 1500s since, and a few Cummins. I drive a lot to say the least. My current 350 is probably the only truck that I’ll ever have for more than 18 months, and that’s cause my half ton sees the majority of my miles. The 350 lives in the garage 95% of the time, and still has 30k miles of trailer on it in 16 months.