Fair enough, but you are also paying to keep a (presumably large) amount of water hot continuously, for good heat exchange that tank must be at about
70oC+ which is rather hot to maintained all the time.I say its personal choice and depends on your circumstances.
Combi works for me: *hot* water whenever I want, and as there is only 2 of us we don't notice the heating cutting out when the shower is on. A large heat storage would be more preferable if my hot water demands during 'heating hours' was excessive. However, I'd say both solutions are far superior to a standard stored water system which in my experience simply causes arguments - albeit they are more expensive
.