Yes, I found that after I posted. Looks like a perfect solution. Is that the option you ended up going with for XX1 Power? I haven't scene a single review of the Stages Cycling power meters yet.
My status is that i am "on hold" now and waiting for what the market will offer. I will start with the original XX1-crank and see what happens. But i think it would be a very nice, but also expensive upgrade, to go for the Stages powermeter with the Hollowgram cranks. Hopefully Stages pm works as it should. It has just been released for sale. I read that the Scott 3rox Racing team (Geoff Kabush) will be sponsored by Stages. So it will be interesting to see if they will race with Stages and perhaps also XX1. The major problem for me right now is that Stages will only be available in the US & Canada at first and i live in Sweden in Europe. "Unfortunately, we cannot ship to those outside of the US and Canada at this time. As a new company, and US based manufacturer, we've made the decision to only sell to North America until we're comfortable growing to support the demand and product outside of that area. We want to ensure we can support our customers in the highest quality manner and we cannot do this until we have our systems in place in other countries."
But who knows what happens during the year. I've also seen lots of pro's switching to XX1 this year, so i hope that will help "pushing" the development of more options as well.
I've used the Power2Max power meter for two years now on my roadbike. It only had one fault. It drifted with temperature. But after the software upgrade last autumn it has been rock solid. So i'm hoping that they will make one too. Not to expensive and very easy to use. Not as light as Stages, but not as heavy as a PowerTap hub either. My spiders weight is 223 grams and the original Rotor spider is 48. So 175 grams extra is not too bad. But Stages is only around 20 grams.