Bought something like 10 packs of these for my little brother, who is learning classical guitar.
They stay in tune quite nice, just restring them properly and you won't have any problems. If you're a beginner, who just needs to change strings time to time (to get nice tone out of them, and no - just can't get nice tone with old strings), then these are for you.
For the price, you just can't go wrong with this product. They work as a perfect backup strings.
And if my little brother is happy with them, you should be too.
Overall: 8/10