I'm not sure what is OEM on the Thrux other than what you already have. OEM on the Bonnie is either a Metz or a Battlax BT-45.
Mine came with the BT-45s. I got 9000 miles out of my first rear and 13000 out of the front. Both had at least 2 or 3 thousand miles of tread left on them. I changed the rear because I had a flat and it was getting close to being changed anyway. And the front because it developed some moderate cupping around 12K and I was tired of the vibration, especially on tours. Around locally I didn't care.
So I got good mileage. I put another BT-45 on the rear and my indy mech said that the new Dunlop 404s were wearing well so I put that on the front. The 404s are available for both front and rear.
Several of the hard riding guys here say that they have worn out BT-45s in 4 to 6 thousand miles. So HOW you ride makes a LOT of difference.
Monte