How much longer though?? I love my showers but have had to put up with having a crap shower each day for the past 7 or so years, with water going in all directions apart from on me. I have tried different shower heads but they all block the same. I can now have a shower with the water actually getting me wet, and not the just the walls & floor. You say that the caked on scale may have been removed after time - but judging by the amount I got out of the system on a bi-weekly basis this would not have happened, I presume that the scale builds up to a certain extent but doesn't take hold as easy as normal and is then ejected as little bits. I would rather pay out to fit a new shower unit every 10 years or so once scaled up than have to endure a crappy shower.