His page on how to fit a bike is very informative and his lighting section is fantastic, but his phone skills do suck. Everyone has their foibles.
I've purchased several lights from him and some other odds and ends such as pit locks. I knew what I wanted before I ordered, used a credit card, and everything was shipped promptly.
When I need bike esoterica Peter is one of the places I regularly look; Harris and Wallingford being the other regulars.