OK, I am so fed up with different plumbers and all their different
opinions. Can any of you help?

I have a very simple question and I hope its a straight forward
answer. I will miss out on the problem and suggested solutions and
hope this can be answered without the details.

Q Would you be happy keeping 8mm microbore thoughout your house (with
flow problems) or would you upgrade all to 15mm?

I realise that you may want more details but I'm not gonna give them.
This is the most basic difference 3 plumbers have told me.

No. 1 wants to change all pipes to 15mm
No. 2 wants to change only the 6mm pipe to 15mm
No. 3 wants to keep the 8mm

Please help. Its doing my head in!

Many thanks
Rebecca