Originally Posted by schoflyer
You will likely want to leave your luggage first. (Departures Level up from where you exit customs.) THen proceed to the JR where you exchange your voucher.
What are your dates. I'm not familiar with T1 left luggage. ANA moves to T1 June 2. What airlines?
There is a left luggage place in the north terminal on the arrivals level in T1 -- it's to your left as you exit. I used it about 8 weeks ago. Note that left luggage at Narita isn't cheap, for a large suitcase it's Y800/day, for "regular" size it's Y500/day. This is charged on a calendar day basis, i.e., you drop on Monday and pick up on Tuesday, it's counted as 2 days.
No clue yet about the new building in T1.
I would not recommend taking the JR Rapid, I'd pay the Y1990 for the Keisei Skyliner and change at Nippori -- the Rapid seems to take forever to me, including waiting for 5-10 minutes at some stations like Sakura or Chiba.