I think the usefulness of these machines depends a lot on the type of patient population you are serving. We did a test run on a Cellavision for about a month. We were a fairly small hospital but serviced a cancer center. We found that it took about 1 minute less to do a normal manual diff and on the abnormal diffs it was taking us anywhere from 10-15 minutes more per diff because the machine was incorrectly classifying so many cells. We weren't terribly impressed and ended up deciding it would save us time to continue to do them manually. Also on questionable cells and RBC inclusions it is more difficult to differentiate certain cells when you cannot focus in or out.