I went through the same dilemma 2 years ago. I have an '07 Crewmax and wanted to go duals. More for the look than anything else.
I started with a Magnaflow dual set up and it lasted 1 day before it came off. It droned like crazy and the quality was******anyways.
Then I picked up a slightly used factory TRD dual. Much better but still droned a bit. All the exhausts developed a howl around 1400rpm up to 1900rpm range. As you accelerate through each gear it would drone in that range then disappear so it wasn't too bad. Unfortunately, highway speed in 5th and 6th gears stays right in that range so the drone stayed and got annoying. It got almost unbearable when towing. I kept it on for a year before going back to stock again.
I then used the factory muffler and had a Y pipe made up so I could still use the TRD dual tail pipes. Best of both worlds. Stock sound, dual look, and no droning.
Still have the TRD dual in/out muffler sitting in the garage if you want to try it.
