This clearly indicates you know nothing of heating and water systems.
Using
a combi with a normal tank and cylinder, it is best to have only the
shower
off the combi giving high pressure mains pressure showers with silly,
noisy,
prone to failing pump, and all other hot outlets off the cylinder. To do
what you did is foolish.

Sorry but I can't agree. No combi will give a high pressure shower,
especially in winter when the flow rate has to be reduced for effective
water heating. They also rely on high pressure supply which some may not
have! Now I mean high pressure - not good pressure. I have "hotel" pressure
at my showers.

The noisy pump.... yes I'll give you that but to be honest I don't hear it
because I have mine in the cylinder cupboard. I have also had the same pump
for three years and it is used six times a day - it has never failed! AND if
it does that's fine too because at £250 it won't bankrupt me. We have to pay
for using things and at this rate it's cheap!

Some do say that I did it back to front but doing things your way a good
bath fill would empty the hot cylinder leaving the rest of the house
(kitchen, utility, garage, etc.) with no HW until it re-heated. My way
(which incidentally is agreed upon by many) allows any tap to have endless
HW and the cylinder is only used for pumped showers.

I'm not saying you're wrong or I am right. Each to their own. The way I did
it suits me fine and if i had my time over I'd do it the same way.