I have casted the 7wt 9 foot xi3 and one. I liked the one more for my casting style. However, everyone likes different things and casts different so I would encourage you to cast them yourself at one of the local shops. I also like the NRX rods. I have not casted the winstons or scotts as referenced in the above post. Anil at puget sound fly co 253 472 2420 would be a good resourse to maybe verbally highlight the differences between some of the rods and 9 foot versus 9'6", but again its best if you cast them and see what you prefer. (I like just the 9 foot rods as oposed to 9 foot 6 inch for beach fishing)
I can't answer for the Winston, Echo, and Scott rods. For my own casting style, I found that the XIs are very nice. I have a 12 wt. and the first casts were near 80 ft. and I'm a hack, admittedly. They are strong and responsive. Gig Harbor Fly Shops test was interesting but I wouldn't say conclusive except in the minds of those particular guys. I'd say the best thing to do would be to try both the One and an Xi3 if you are wanting one of the two. Sage makes incredible rods as you already know. The warranty is great and the workmanship is superb. I'd weigh all of the factors before I dropped $800+ on another rod.
I use a 9' 6 weight xi3 for a lot of my coho and beach fishing. I use a 10' 4 weight for my cutty fishing in the Fraser valley. I love the sensitivity of the ONE but I'll never give up the xi3. That rod can bend nicely on a 12" cutty, and kick a chums ass all in the same morning.