I would love horizontal progression. Like a few posters have mentioned in previous posts, it would keep older gear relevant. I also would like SE to take this one step further, and keep older areas relevant. Having at least partial horizontal progression is great for longevity - expanding on what is available then incrementing upwards slowly. The current vertical method is not good for longevity and really not a good way to keep a quality game going for a long time. Hopefully some changes are made