1. the package offering the functionality I needed was much more complex than needed and my solution implementing that functionality was much simpler (because it implemented only what I needed)
2. was not the best quality, because it was written by someone who was not necessarily better than me, or didn't spent enough time understanding the problem he was trying to solve
Having said that generally popular packages are good quality, although even then #1 applies, if you need just small functionality of a specific package try implement it yourself, it might turn out that the problem was not as hard as you thought and because you're just implementing what you need it might be more elegant.
1. the package offering the functionality I needed was much more complex than needed and my solution implementing that functionality was much simpler (because it implemented only what I needed) 2. was not the best quality, because it was written by someone who was not necessarily better than me, or didn't spent enough time understanding the problem he was trying to solve
Having said that generally popular packages are good quality, although even then #1 applies, if you need just small functionality of a specific package try implement it yourself, it might turn out that the problem was not as hard as you thought and because you're just implementing what you need it might be more elegant.