Operation Samahan a long-time user of ClearHealth, has been written up at Linux.com. From the article:

“We were able to cope with all the standard changes in billing really easily,” Bringas recalls. “In the meantime, we had all these complaints from other clinics, who were saying, ‘Oh my gosh, we haven’t gotten paid in six months because our [software] vendors are very slow in keeping up with these changes.’ We were so glad that we got out of that system.”