Bott are the designer range, my mate had his Dispatch kitted out by them it looked great and was very personalised for his needs. He looked at Tevo too and thought it was a bit standard for his needs.
Pete
Before you choose whatever system make sure you have your "Decent" mains water measured flow and pressure.
Sustained 18l per minute from the boiler does not mean from all outlets, it will be halved if 2 outlets are calling for hot water.
Washing machine cold feed still takes from the cold...
Could be a few things, you may have a defective pressure/temp relief valve. Sometimes these do not seat correctly after testing (servicing)
What is the pressure like from your hot taps?
Pete
We us Fila, we buy it rom Topps tiles. It is a clear solvent based liquid, it does not affect the grout when we use it so it should be ok. Do a test area first.
Pete
The heat from the primary exchanger will dissipate very quickly into the main primaries, if it cuts off when the heat is gone it may actually be more efficient than a timed unit.
Pete
I would advise using a decoupling membrane (Ditra) under the tiles as you will have movement and this allows for such.It also tanks the room which is handy in a shower room.
Pete
Since it is a considerable sized project I would advise you get in another 2 or 3 quotes. Do not get" a lot more quotes" as if the prices are similar then you are wasting your time and theirs. Do however get an itemised detailed quote as you mention.
Pete