The most important thing to remember when booking is that this is not a hotel, it is an apartment. There is no on-site restaurant, so you do have to fend for yourself. However, that aside, this building is only a short 10min walk from the city centre and is in the quiet Helsinki neighbourhood of Töölö. I walked the short 5min walk round to the Scandic Park Hotel and had breakfast there or you can use the Moroccan restaurant directly across the road from the hotel and receive a 10% discount on your order.
The building is early 20th Century and has two sides, A and B. I stayed in Room 251 which was right at the top of the building on staircase B. It was a lovely spacious room with sofa, dining table and chairs, bathroom with shower and toilet, single bed and kitchen area. The kitchen had fridge, microwave and all manner of crockery that you could make use of. There was also a little balcony terrace that you could sit out on and see across the city.
I stayed at the Hellsten for four nights and it was so quiet that I slept like a baby each night. The room was not cleaned during the time I was there, but to be honest that did not really bother me as I didnt make use of the kitchen and only really used the room to sleep.