Image quality have been added to the Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens Review.
We should expect this lens to deliver iamge quality similar to the Canon EF-S 18-135mm f/3.5-5.6 IS STM Lens. Here is the comparison: Canon EF-S 18-135mm IS USM vs IS STM Lens.
The 18-135 IS USM is a really nice lens to use - a pleasure to walk around with.
B&H has the Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens in stock. This lens is also available in the Canon EOS 80D kit, but unusual is that there is no savings over buying the lens and 80D separately.