Stayed for 3 nightsmidweek, in January 2012. I found it to be fine. It was a five minute walk from Kilburn Park underground station (Bakerlooline), turn left from station. Staff at SO were polite and helpful. I had a room on the back of the block which cost a little more as I wanted to be away from street noise. The first night I did hear a little noise/music from what I assumed was the pub at street level but it didn't seem to last long.
The apartment was fine, clean, although carpet was a little past it's sell by date. A very large bedroom, large bed, four pillows, duvet I thought the bed might be uncomfortable as the mattress "boinged " but I found it comfortable and had none of my usual back ache. The bathroom was fine with a bath and over bath shower, The switch for the heated towel rail is on the outer wall. As commented before there was no hairdrier but forwarned I had taken my own. I had also taken a small kitchen knife and scissors which proved useful as there was only a large knife provided. There were plenty of other utensils and a full complement of cutlery crockery etc. Tea towel, sponge mop and washing up liquid provided
The kitchen was part of a large lounge area with a slightly beat up sofa , a dining table and four chairs, also a TV and what appeared to be a DVD player although I didn't use it.
The block is directly over a Tesco Express but a mauch larger Sainsurys and M and S were only a five min walk away as well as numerous other shops it is truly a high street. As well as the underground station a newer overground station Kilburn High Road is two minutes away and that will whisk you to Euston Station (close to Kings Cross) in less than 20 mins, The underground took about 40 mins with one change.
I didn't use any local restaurants but I did use the Golden Egg Pub up the road. Pleasant atmosphere friendly staff, cheap pub food and beer/wine ,there are other pubs in the area to suit other tastes.
I found SO to be fine for my needs and at a reasonable price- note the apatment is not serviced as such although waste bins in kitchen/bathroom emptied every day.

We went to So quartier wanting to stay for 11 days. The noise coming from the pub/club downstairs was so loud that we didnt sleep until 4 in the morning. Then at 6:30 when the shops (Tesco) opened below it was noisy again! The stuff i must say was friendly although I never got a wheelchair seat for the disabled shower eventhough i called and asked for it 5 days before arriving! Unless they put triple windows i dont think anyone will be able to stay there without earplugs! Good location, friendly eager to help stuff but extremely NOISY... I left on day 2.
Alexis (disabled) with wife and son

I will put it blunt.
Website stated hairdryer in every room... 2 hairdryers in whole hotel. There was a queue of women waiting with wet hair and the receptionist tried to give £5 to one of the customers and said "There's a shop around the corner go buy one"

We had to wait 45minutes to leave our room because they didn't have a key for our room.

They stated on-site parking... Not on site... no where near.

Shower didn't work.

5 out of 6 of the staff where ill mannered and rude.

The manager is completely disrespectful.

Worst stay in London I have ever experienced. So much so we left London 6 hours early.

I would not recommend this place to anyone.

Booked apartment for midweek stay with sister & daughter. Very handy for transport links especially if travelling to London Euston. Also within close walking distance to underground. Apartment clean and tidy although somewhat lacking in cutlery & utensils. However, when this was hightlighted to reception they went out of their way to provide what was lacking, specifically a DVD player. Reception staff were very helpful and it was also reassuring that there was someone on desk 24 hours. Enjoyable stay close to lots of local amenities(Tesco, Sainsburys & Marks & Spencer)