Reliable washers.

[ppppenguin]

I too appreciate a warm airing cupboard. With a well insulated cylinder most of the heat will be coming from the pipework. Like Mark, I appreciate having a backup immersion for DHW. I don't like long dead legs. In my bathroom the pipework from the cylinder to the taps is short so problem. It's rather further to the kitchen tap. Most of the run is insulated but it takes quite a few seconds to get hot water unless it's been used recently. The downsatairs loo has a a run that's far too long. Usually just wash hands in cold water. A little 3kW instantaneous water heater would be better there but it won't happen.

If you have long DHW runs then a circulating system will work. More pipework, need good insulation and electricity to run the circulating pump. Often used for washrooms in offices and factories.