I used them for several years when they were known as D&A Consultants before being bought out by another consulting firm in 2000 or 2001 - can't remember exactly but it was many years ago! The transition from one management team/company into another had some challenges with continuity of service level agreements (SLAs) between clients who transitioned together versus those that didn't.
They also lost my client base at this time due to their acquisition so there are no happy customers left over from our period working closely with these guys back then either :) Great people though; great consultants too.