Haven't used them personally, but I have made my own enamel pins in the past (I think I went with Made By Cooper). Be aware that a fast turnaround often just isn't possible with pins due to them being manufactured in China. Even UK-based companies will use a Chinese supplier, though they probably won't tell you this directly. Mine took about 4 months to arrive from the date of ordering.
Thanks. I have read some mixed reviews on m b c. The guys at Studio Dais said they offer a 2 week turnaround so was more curious about that. Cheers anyway. We have a few weeks yet before we need to make a choice.