I stayed at Per's studio from Sept. 7th to Sept 10th. It is as described and extremely well located. As a female travelling alone, one is always concerned with the location of where we're residing, but there are no concerns here. I often arrived late at night and never felt any danger. But Stockholm in general is very safe. The studio is located close to the subway as well as to various buses. It is also walking distance from Djurgarden island and I walked from the studio to the Vasa museum. Great location. Also there is an amazing bakery not far from the apartment on Valhallavegen street between the subway & the apartment (don't remember the name) but the breads, croissants, etc are amazing. I went there for breakfast a couple of times and I loved it.
Per also made sure that I had access to certain amenities (e.g. shampoo - I forgot mine at the last place I stayed so thank you Per). There's tea, coffee & snacks that are greatly appreciated.
The bed is reasonably comfortable but if someone has a bad back (like I do) then perhaps a firmer mattress would be warranted. Other than that, the studio is great. I never meet Per but he always answered promptly to any of my requests.