No never specifically tried the JG emerger.
If i remember rightly it fishes similar to Wyatts DHE,a fly that is great tied with Snowshoe hare.Do you reckon the split wing makes a diffference? I have a problem getting past my CDC spiders during a rise but have spent ages wondering about the merits of winging flies
What type of bodies do you use, i take it you tie them in a variety of colours to match the various hatches?
Photos are always cool too.
Sandy