I stayed at Kaspars' place for a month. I was satisfied with my stay. The apartment is in a great location!
You can walk to oldtown in 40 minutes. Right by the property is a huge shopping mall with a lot of things to do (Riga Plaza), and there are parks and landmarks around.
Keep in mind that there's a family with children living upstairs, so there will be some noise. However, it didn't bother me much. At 22:00, it always was graveyard silent.
To my surprise, there's a 'No guests' policy. If you want someone to come over, you must register them as official guests for extra pay.
To be fair, 'No guests allowed' was written in the description, which I overlooked.