Well, I agree that you need to get down to catch winter fish, but my opinion is that when you make a decision to swing flies, you are giving up your opportunity to effectively fish water deeper than about 6 feet. Using T-20 to try and reach deeper lies will likely result in more bursitis than fish (you'll be lucky to get 6" deeper than you would with T-14 unless you are using a full sink line), and casting it will be torture, at best. If you want to swing for steelhead, walk right by the water deeper than about 6 feet. My two cents. There's plenty of water on any river that holds fish and is less than 8 feet deep. Focus on that, or break out the gear rod (which I have been known to do).