I don't rate Bosch at all. Maybe I'm unlucky but have had two faulty Bosch appliances now that have gone wrong after the warranty expired. In both cases, the products were not used that much either.
1. A £720 washer/dryer (AO price, was £800 elsewhere). I used it for a year before moving out of the property and leaving it empty for at least a year. It started playing up about 6 months after a tenant moved in. Had to be repaired two or three times. Luckily I took out a Domestic and General warranty from them rather than paying a one off fee after the first repair so the further repairs(s) were free.
2. A £60 kettle that lasted 2 years 8 months before starting to leak from the base. It was completely unused for the most of 5 months and the rest of that time been used at weekends only. Have discussed this with them but their adamant their stuff is good **** so is not a manufacturing fault as it, erm, lasted two years. I couldn't be bothered to argue the case that things can be built with a MTBF just to outlast a warranty.
I'm more disappointed with the kettle to be honest. All it has to do is boil water for goodness sake. Even cheap ones should be lasting 5-10years +. Now will end up in landfill - more crap built to a price point/built not to last too long that will be damaging our environment.
Also have a Bosch iron that's still working after 5 years but doesn't see heavy use although it's never been a particularly good iron either (really difficult to get rid of creases).
Best items I've had are a Servis fridge/freezer(co-op own brand I think) that is still working in rental property after 14 years, and a Fridgaire kettle. It was a jug type with heating done by an immersion coil, rather than a heat plate which is all we seem to have these days. It lasted years and only threw it away when I moved house and it was completely off colour (it was white originally). Oh, a Russell Hobbs toaster is still going strong too after about 14 years. An Indesit washer/dryer also lasted 7+ years too, bought I believe before the current run on producing cheapness.
I now have a Miele washing machine. £850 from memory. So far so good, has lasted since moving into my current house, albeit, only 3 years so far. It does wobble a bit sometimes (heavy items) but I put that down to new build **** poor quality floorboards flexing

. It's a solid applicance even with metal hinges.
Problem with Calgon is that they're pretty costly and might not be worth it. Just done quick calc and 2 washes a week = £37.44 on Calgon a year. Washing at lower temps = less limecale anyway.