Ash catchers serve up a number of benefits. For example, an ashcatcher will keep your bong a lot cleaner, especially if you are a relaxed smoker that uses your favorite waterpipe daily.
Ash catchers essentially catch-all that nasty crud and residue from smoking. This Can have an impact on how your rips taste. It can also allow you to get bigger rips over a long period of time without deep cleaning your bong. This smoker accessory also has added percs (literally), giving you a smoother, more flavorful hit.