Brendan O’Brien had everything one might hope for in a copyeditor – patience, attention to detail, pragmatism and good judgement.
Anthony White. In 'Preface', Irish Parliamentarians: Deputies and Senators 1918–2018 (Institute of Public Administration).

I cannot express adequately my debt to Brendan O’Brien, the publisher’s editorial consultant, who helped me negotiate the difficult linguistic waters that seem to divide the new and the old worlds. Brendan’s keen editorial eye and his enviable grasp of Irish history and culture guided me deftly through some murky and sometimes choppy waters, and I am most grateful.
Dr Robert K. O'Neill, Director of the John J. Burns Library at Boston College. In 'Acknowledgements', A Visitor’s Guide to Irish Libraries, Archives and Ancestral Heritage Centres (Ulster Historical Foundation).

I am very grateful to the editor chosen by the IPA, Brendan O'Brien. He not only did a very professional job of editing the text but also gave me help and encouragement along the way.
Noel Dorr, former Irish representative on the United Nations Security Council and Irish Ambassador to the UK. In 'Acknowledgements', Ireland at the United Nations: Memories of the Early Years (Institute of Public Administration).

Brendan O'Brien, who edited the earlier book, has again been editor on this occasion. He has been very efficient and professional, as I knew would be the case, and I am grateful to him once again for the help and encouragement he has given me along the way.
Noel Dorr. In 'Acknowledgements', A Small State at the Top Table: Memories of Ireland on the UN Security Council, 1981–82 (Institute of Public Administration).

I worked with Brendan when he proofread my PhD thesis in April 2011. The level of detail with which he examined the content, style and grammar was quite incredible. He worked very quickly, emailing the document back to me with all edits tracked. He also provided a page of further issues for me to consider revising. Brendan's meticulousness provided a level of polish on the final thesis. His rates are extremely competitive for this supreme level of professionalism. I would recommend Brendan O'Brien without hesitation for any writing, editing or proofreading work.
Fiona McIver PhD, specialist in design–business partnership. LinkedIn.

Brendan was one of the main freelance editors I used when I was working at Psychology Press. His work was always top-quality; he was a very reliable editor and was lovely to work with.
Eleanor Wood, Project Editor at John Wiley and Sons. LinkedIn.

Dear Debra,

As we begin to see the “light at the end of the tunnel” on our manuscript, we feel compelled to communicate to you our very great satisfaction with Brendan O’Brien’s work editing the second edition of Families with Futures: A Survey of Family Studies Into the Twenty-first Century.

Although we consider ourselves more than respectable writers, Mr. O’Brien took our writing to a much higher level.  We compliment not only his meticulous attention to detail with regard to grammar and punctuation, but also his keen eye in collating across sections of the manuscript

He even offered the occasional, gentle suggestion that a passage may not have been as clear as it could be.

We were particularly impressed with the speed at which he accomplished such a high quality of work, as well as his prompt responsiveness to our queries.  Throughout it all, we knew we had on our side not only a gifted professional, but also a gracious colleague.

 With this letter, we extend both our sincere thanks and our strong sense that Brendan O’Brien is a tremendous asset to the Taylor & Francis/Routledge team!

Janet R. Grochowski, PhD, Professor and Chair, Marie and Robert Jackson Professor of Education, College of Saint Benedict/Saint John’s University
Meg Wilkes Karraker, PhD, Professor of Sociology and Family Business Center Fellow, University of St. Thomas. Letter to publisher.

 I've included Brendan in the email as I do want to take this opportunity to say thank you very much for the work that you put in ... I am very proud of the work and care that went into producing Real Maths and in particular Real Maths 2 and that was in no small part thanks to Brendan.
Paula Mangan, author.

To an expert from Shakespeare to The Supremes.
Inscription on signed copy of Original Sin in a Brave New World: An Account of the Negotiation of the Treaty of Amsterdam by Bobby McDonagh, Irish negotiator (Institute of European Affairs).