This is really helpful - can't seem to PM you? Do you have an email address I could get in touch with you on?
Gareth's site is here: https://blueandwhitemortgages.co.uk/contact/
Just echoing what others have said - we used Gareth for a re-mortgage earlier this year and although there's a degree of luck about the timing of these things, the deal he got us will save us thousands of pounds over the length of the fixed rate term, and it was all handled smoothly and efficiently.