i have had a hot ionic system for over 3yrs now. it is brilliant but, they are expensive to buy, run, and repair etc .however, cleaning results with hot water is second to none!, i was without hot water for a few weeks and found it much more difficult to maintain my usual high standards. i have only had spotting once, which was not my fault. and no matter how much i cleaned it, it reappeared after a few days, I tested my water on other windows with no problems, could not convince customer that it was not my water even cleaned them trad and spots came back. i am
convinced that as long as your water is pure, the spotting comes off the frames ie paintwork alluminium frames etc . it is all about rinsing with care IONICS systems are in my opinion the best. you get what you pay for.