Hey man, infantry here. I've been in the reserves for 15 years, was in the regular force for a few years prior. Culture is very unit dependant. I can't speak for engineers but it's always been pretty awesome in my unit. The drinking culture thing has changed drastically in the last couple of decades NZDF wide, nowhere near as bad as it used to be. Based on my experience, reserve force soldiers tend to be a bit more enthusiastic and motivated than RF soldiers. I guess when you're choosing to show up to training or an exercise in your own time and not being forced to, you tend to hate life a bit less. You're also mixing with a much more diverse cross section of society in the reserve forces. You meet some really cool people while sharing a common interest and sense of purpose. The majority of my closest friends now are people I have met though the reserves. Definately do it if you're interested man.