On the good side, it's easy to replace, you don't need a plumber, 10 minute job if you follow the instructions.
HOWEVER (i) my first water heater died prematurely, (2) the unit is NOT serviceable so you have to buy a replacement, (3) the replacement part is too expensive, (4) ...partly b/c you can only buy a set including a water filter that I don't need and just had to toss. It's also not energy efficient if you care about that.