Olly's place is in an excellent location, if you want to be central to the CBD and all the arts/entertainment that Wellington has to offer. The apartment is in a alley off Cuba Street; it's a little edgy, and the building is pretty run-down on the outside, but the location and interior more than make up for this.
However, I'd only recommend Olly's place if you're planning to check-in before 7pm. If you're arriving after 7pm then the access gate to the apartment block is locked and there is no way of entering other than waiting for someone to come through the gate and let you through (the alternative, an elevator with a code, is broken). I had to wait around 30 minutes for a kind soul to let me through the gates; not ideal, at 9pm at night, standing there by yourself. For this reason, it's also not great for anyone who would struggle with pulling their luggage up a steep flight of stairs. If you can look beyond this point, then go ahead and book!