SAVE BEFORE ATTEMPTING
Hi all, I believe I may have found a possible set location for the X-01 power armor. It's West of a location called "Custom House Tower", which is on the shore East of Goodneighbor or East/North East of Diamond City. The power armor should be in a building called "Court 34". It's unmarked however, and although it's directly West of Custom House Tower, it can be hard to find.
Once you're in, take the elevator up. Once you're on the roof, an alarm will sound and two high level robots will come out. For me, one was an assaultron and the other a sentry bot. Once you kill both, you'll notice two rooms that the robots came out of, both of which have red buttons. Press both, and the room in the middle of the area should open. Inside you'll see a power armor.
Check the power armor's inventory, regardless of its appearance
For me, the power armor appeared to be an incomplete set of T-45 power armor. As you can imagine, I was pretty bummed. When I went into the inventory, however, it all turned into X-01 armor. As in, a full set, helmet and all.
I say that this may be a set location, as I was level 29 when I found this, a level much lower than what most people claim it spawns at. Due to the armor changing appearance, it is important to note that this may be a bug, and subject to future patches.
Tell me if this works for anybody else. I'm curious as to whether or not I got this by chance or if it's really a set location.