Yeah, I held off on that one cause I'd heard from an office-mate that it ramps up the difficulty rather suddenly. Leveled up with some of the Diamond City & Brotherhood of Steel fetch quests, building stuff at the settlements I liberated, and completing the 'Silver Shroud' (I believe it was called) questline ... which was definitely the best side quest so far in the game.
Went and tackled that mission around level 20 and it wasn't too bad, still a challenge but not insurmountable ... be careful you don't enable the 'Glowing' version while you're still fighting the 'Queen' one or you'll be in trouble though. The glowing one's release happens when you enter a certain room in the building and you DON'T want it after you while you're trying to take down the Queen.
Anyways, yeah ... awesome game, loads of fun, just like FO3 and FONV and Skyrim all were. I'm like 70 hours in and feel like I've barely started...and actually, that's true from what I understand. SOOOO much to do in this game it's almost ridiculous.