Annoying on the magazine. one extra is about alll you should need anyway. Gets worse than that the wife should be handling you the modern musket! (or be backing you up and take over the firing duties while you load up with the long term combat stuff)
What happens when magazine #1 fails? And you need the gun? What if you need that 17th shot (assuming 9mm, that is)?
I'll quote Clint Smith, in reference to the number of magazines (including the one in your gun) you should carry,
One is none.
Two is One.
Three is where you should be.
There's absolutely no reason that gun shouldn't come with at least 2 mags. Coming with one is just ridiculous. I know, they did it to keep the cost down. But most would gladly pay $440 for the gun instead of $400, just to have an extra mag.
You're justifying Sig going cheap on the gun, just because it's the one you have. No need to justify your choice. I have a laundry list of complaints with most of my guns...none are perfect. But really, only one magazine? And when we bought my wife's, there wasn't a single one in town for over 2 months. Had to buy them direct from Sig...and they were charging $45 a piece, not including shipping. Ridiculous.