We've had a great experience with Adia PR. Their account director Eleanor has been instrumental in helping us obtain coverage from top-tier news organisations (i.e. the Telegraph) as well as vertical-specific publications like Brand Republic, Start Up Donut, IT Donut etc that are very closely aligned with our target customers.
They have a great understanding of our business and are always willing to go the extra mile. I would highly recommend them to anyone, specially startups.