In reply to Jim Houghton:
The Clog Centre harness was the standard for years - a really wide adjustment range, and tough as old boots. But there are a couple of really frustrating aspects - they have no gear loops at all, and the old fashioned buckles can be completely undone to leave the harness as a confusing mess of straps.
For those reasons, when I retire mine, I'll probably replace with DMM Brenin. If I worked solely with children I'd probably get Centre Alpine for the higher tie-in loop, but as I also teach ropework classes I'd rather have the belay loop in the 'usual' orientation.