I've had trout take me into the backing about 10 times in the last 6 years. Not much but when you do hook that wild/native 16/18/20+ fish on a 5-7x tippet on a river watch out. 2 weeks ago I was in Yellowstone fighting rainbows and browns the biggest one of which fought me for 20 min. and only took 20-30yds of backing. The next, a brown of 18", took me well into 3/4s of my backing that I could see the end coming up and had to order my guide to get on the boat and catch him. 30 minutes later I landed that bruiser after a long chase on the river. He took me into my backing 4 times and after landing him noticed he had bent my hook. My flies had bent hooks 4 different times on this same river. My Lamson was a bit overfilled with backing but this trip I was grateful for all the extra I had. I don't think I would go to gel spun but I might consider using 15 lb backing to get more.