Experience from a Brit
I got some important paperwork done here by a helpful lady who spoke English and provided excellent customer service.
It involved 2 members of staff, international mail, and some official seals.
Cost = free
I then went to the British Embassy and was met by a miserable woman who made me feel like an inconvenience to her repetitive day.
I needed a standard letter which would involve them hitting the "print" button on some letter-head paper.
Cost = ~$60