It's a fair review but I think that the overall impression that you leave is that it is a niche car. I would push back on that observation and would suggest that two main issues are apparently leading you to that conclusion; namely, price and fuel consumption.
Let's start with fuel consumption. I know C&G went by your own personal experience (which is completely understandable) but there is a lot of real world data out there about real world Volt owners. As a couple of people mentioned you can go to voltstats.net to see what real drivers are doing. What you see is that the average of the self-reporting fleet is a little under 130 MPG. But if you take a good look at the data you will see that if you throw out the top 10 percent and the bottom 10 percent and look at the bulk of the drivers in the middle the average MPG goes up quite a bit.
Now to personalize it a little, I have a 50 mile round trip commute and I'm averaging about 336 MPG. Crunching the numbers that means that I'm saving about $2,000 a year over the operating costs of my last car (a 30 MPG car). While I plan to own the Volt far longer than 5 years, if you make an assumption that gas prices and electricity prices stay the same, over the course of 5 years I'm saving $10,000 in operating costs over your standard car that gets 30 MPG. My net price for the Volt was $35k and so I'm essentially getting a high quality, fun to drive car that would cost me the same over 5 years as if I bought a car that cost $25k.
Another way to look at it is that the average driver goes somewhere between 12,000 and 15,000 miles per year. That is the equivalent of 32 to 41 miles per day. Knowing this GM designed the Volt with an EV range of 25 to 50 miles per charge so that most drivers can go most days without using a drop of gas and thus saving themselves tons of money.
Once you understand the interplay between fuel consumption and the price, you come to understand that the Volt isn't really a niche car, it is a high value car that is just plain fun to drive. Of course, most people don't understand that as well as Volt owners do. But you are in a position to better understand this dynamic and explain it to your readers.