[Update: I've been told that dice rolls might determine the set of armor you get. Post level 26, it's more likely to be X-01, but may vary. Of the four times I tried, it was a full X-01 suit. Be sure to save beforehand in case you don't get what you're looking for.]
The default power armor in Fallout 4 might as well be made of wet cardboard. A few mines, a couple of precise shots to the chrome kneecaps, and those hunks of junk disintegrate like a saltine in hot soup. But that salty, savory taste? It’s blood, imaginary blood, because the armor did diddly besides bring your fashion level up a few measly notches. Luckily, there’s a way to take care of not-dying and power armor sex appeal in a quick, relatively difficult journey once you hit level 26 or so.
The X-01 armor may look familiar to Fallout fans, likely because it’s featured on the box art for Fallout 2. Those with the entirety of the Fallout lore over-encumbering their mental inventory will also know that the armor has Enclave associations, but it usually just poses as high-level or rare gear in each game. Before I found it in Fallout 4, I rarely used power armor, but now I never want to be out of it. My suit looks cool and takes much, much more damage before repairs are required. Here’s how to get your own.
Where to go
Once you’re out of the vault and level 26 or so, it’s possible to find the X-01 suit. Players have reported that the suit won’t spawn before then, though you can still find another suit of power armor at the location in this guide regardless of your level. It just won’t be as neat. Don’t you want power armor with eyes that glow?
The armor is located on a rooftop not far from the eastern coast. It's not a marked location, but is easy to find if you head east from Good Neighbor until you reach a building called "Custom House Tower". From the Custom House Tower, turn west until you see a turquoise building. Circle the building until you find its only entrance. A sign should read "35 Court". When you find it, go inside, look left and you should see an elevator. Head on up.
'Shut down' some bots
Once you’re upstairs, you’ll should see three doors. The center door contains our treasure, it's locked tight. After a moment, some lights will flash and an Assaultron and a Sentry Bot will emerge from each side door. If you’re not specced out to do tons of damage to angry metal people or you’re barely level 26, it can be a tough fight. Good thing it’s so easy to cheese enemies in Fallout 4.
To easily take care of the robots, I ran off the ledge opposite the main door and onto a small overhang. The robots followed, so I navigated around the corner to out of their line of fire, hopped off the ledge to the ground level (consider taking some Med-X and quicksaving), and ran back upstairs. Now it’s possible to chip away at the robots’ health from above. The term ‘artificial intelligence’ carries layers of meaning here.
Ogle at the armor
When they're done for, you'll have to press a button in each of the robot closets to open the center door. After a few dramatic mechanical noises, the center door will open, and you can claim the new suit. Be sure to jump off the roof and play with the flashlight eyes as soon as possible. Once you're tired of clapping your hands together, take a look at the X-01's stats (and clap some more).
Congratulations, hip owner of the X-01 power armor. Enjoy exploring the wasteland with flashlight eyes and ice cool aesthetic. The extra safety is a nice perk too, I guess. And that taste in your mouth? It’s not blood. It’s nothing. Enjoy it, because when a few suicidal supermutants decide to hug you close and explode right up in your metal grill, nothing sure tastes good.