ATPase versus Immunohistochemistry for fiber typing in muscle biopsies: which is better?

When I receive a complex muscle biopsy case, I send my specimens to the excellent muscle specialists at the University of Iowa Department of Pathology. I recently got a consultation report back from Dr. Leslie Bruch (pictured) at that institution. In her report, she noted that immunoperoxidase staining for slow and fast myosin heavy chains were performed to assess fiber type distribution. For that purpose, I use ATPase at pH 9.4 and 4.6. I asked Dr. Bruch whether there were any advantages to the immunohistochemistry approach versus ATPase. Here's her response: "The reasons we changed to immunohistochemistry for fiber typing here was that it is more consistently reliable than our ATPase stains, as well as less expensive in terms of tech time and reagents, etc. One limitation is that you cannot subtype the type II fibers as you can with using ATPase at 3 different pHs. We have been happy with it since the change."

If anyone has any further thoughts on the relative advantages of the two methodologies, please comment.