Bit of feedback based on a couple of hours use:
I’m pretty tall so went for a 170mm drop (on an XL Stumpjumper 29). Bike was in for a service so the LBS swapped out the Spesh command post for the OneUp, hence I can’t comment on how easy it is to fit or set up.
For comparison I’ve only ever used Reverbs and Command Posts. From the off the post feels great, a very smooth action, the return is quite fast but nothing like as fast as the command post. The lever feel is great. I was hoping to re-use the spesh lever but it wasn’t possible in the end. Not at all disappointed as the OneUp lever feels nice, the actuation is quite light but positive and feels good to me. It was also easy to get it in a good position on the bars and it felt immediately intuitive while riding. There is a tiny bit of side to side play in the post but I’ve never had one of any brand that didn’t do this.
I still have a couple of inches of post showing out of the frame but the extra 45mm drop over the command post feels fantastic, the saddle is so much lower on steep stuff that I don’t even know its there now.
Based on a couple of hours use it’s great so far, but will see how it goes over time.