Ah yes, one of my early trips to Japan and I did similar - though I used the SkyAccess direct to Asakusa. That was less idiot-proof as, being an idiot, I hadn't used luggage delivery, didn't check for where the lift to street level was, and ended up putting my back out carrying two massive suitcases up a ridiculous (probably actually quite tame when you're unencumbered and not jetlagged) staircase.