I did alot of GL fishing when I was married. My ex worked for NW airlines, so flew back to see friends in Michigan and Ohio alot. So did some fishing. Will say this.
I used to bring my flyboxes for steelhead here. Mind you, this was pre internet. I was told by phone to bring my steelhead gear and flies to use when I showed up since fish were running. I had a virtually skunked trip using my NW gear. But, did some borrowing of local flies and started catching immediately. I had my OlyPen flies. Lots tied up on 1/0's and the likes. Some smaller, but no smaller then a size 2 with me (since it was winter time). I thoroughly worked my flies. So wasn't holding back and was fishing with confidence. But, no luck at all until I switched to smaller flies. BUT, the rivers were nearly at our summer conditions when I fished there.
"Good angling ethic is not a monopoly practiced just by fly fisherman" - Bill McMillan