Sunchaser raises a good point. Some older vintage boats like my 1977 are designed to operate on 12V DC and propane. Later models like Moon's are designed for more 110V operation with modern AC-powered ice makers, TVs, refers, heating and air conditioning. Therefore, they become more inverter and genset dependent. An inverter failure on my antique means I revert to propane stove for coffee, propane oven for cooking, 12V dc fans and main 12V fridge. Even my HDTV is 12V. No loss of functionality, just a slight inconvenience. Not so on today's vessels like Moonman's fancy, schmancy Sabre.
If the success of my cruise was highly dependent on certain components, I'd plan to carry spares where practical. Until reading Don's blog, I never would have thought to carry a spare inverter. I bet he didn't either. That's the great thing about this site. We can all learn from each other's experiences. But we won't all agree because there is no one-size-fits-all solution to the problems.
I have learned a lot about marine systems in general and my boat's systems in particular by studying the proper way to approach repairs/mods, learning from my and other's mistakes and the advice of those I trust. I am not the world's most gifted mechanic, but I have a pretty good understanding of aircraft and boat systems and can muddle through many jobs not requiring highly specialized tools or skills. I've made my share of mistakes along the way and learned from them, but I also have learned a whole lot about my beloved boat in the process.
A vocal few on this forum feel they need to vehemently argue and publicly dismiss anything that differs from their experience or biases, be it anchors, inverters, boat hooks, docking techniques or varnish choices. Their way is the only way! What they fail to understand is that it is up to each of us to decide which opinions and experiences we'll consider in our own boating life and which we'll ignore.
When I think it might help or entertain others, I'll pass along my experiences. Take it or leave it, but it is what it is....just my opinion or experience. YMMV.