Excellent location. Just a quick, straight shot walk to Shibuya Station and on a side street away from the hustle and bustle. Hajime is correct in noting that the stairs to the loft/bedroom area could be treacherous for children and/or elderly folks. We didn't have an issue, though. Hajime's check-in process is quick and painless and he was a great host in providing us with books and a binder with recommendations for things to do and eat.
Overall, I'd say that this is probably a perfect location for one or two people. Any more and it'd be a tight fit. We really enjoyed our stay and would highly recommend it!