Alpha pots, like the one shown, have rarely let me down personally. However, it has also been my experience that the smaller the diameter of the pot, the more abrasive the wiper tends to be. Keep in mind that pots can only work because the wiper is pressed up against the resistive strip. The implication is that sometimes pots will scrape off small particles of the resistive strip, and they can accumulate, as a form of "dirt" inside the pot, leading to tiny momentary discontinuities as the wiper is rotated.
There are chemical treatments that can repair or avoid this, but the simplest and cheapest alternative is to gently pry up the tabs of the back cover of the pot to remove it and expose the resistive strip. You can then use a cotton-tipped applicator to wipe any residue off the resistive strip.
Additionally, the connection between the solder lugs and the resistive strip is maintained by the little rivets you see in the picture. Every once in a while, a pot may arrive with one or two lugs not providing as snug a fit and connection as one might like. While the back of the pot is off, you can get in there and give the rivets a little "pinch" with your needlenose pliers to secure the connection, before you replace the back cover on the pot.
I have found both of these procedures to help reduce potentially noise potentiometers. And, best of all, unless you have to actually go out and buy the tools, it's free!