Alfred, like you say, try them out and see. They made it past the first hurdle, which is getting them mounted, balanced, holding air and rolling without issue. They've remained smooth and quiet for you so far. I've seen this brand listed through Walmart for a year or so now. I know I didn't have great luck with Antares Comfort A5's through walmart, but I had them on the front of a heavy and heavily used minivan. They were smooth and quiet but wore completely out in 18K miles.
There's so many variables in terms of application and usage for tires, it's impossible to predict how they'll be for you.
IMO, cheapo tires are fine for a small, light car, especially if the car isn't used much.