We had our Big Berkey for over 20 yr. in our S&B and it's still delivering good tasting water. We wash the two black ceramic filters once a year to keep them clean so filtering is as fast as possible.
We also got a Travel Berkey for the TT because it's a little smaller (2 gal vs 2.5 gal) and fits better on the limited counter space. For travel, DW empties the water from the bottom section, flips the top section into the bottom, and stands the combination into the kitchen sink. The bottom section has a rubber ring around the base so there's no damage to the sink or Berkey.
TIP: Berkey filters hold water so don't leave them in a cold TT during freezing temps - they may fracture. Also the metal support stands sold by Berkey are the best (sturdiest) available stands for the unit and are designed to fit each specific unit. The optional water level spigot is not IMHO worth buying. The clear water level is too difficult to see in the tube and the tube seals leak.