Simon's place has all the basics and is nicely decorated. There were a few things their cleaning person had forgotten to leave out for us, but Simon stopped by within a few hours to take care of it. He gave us a great suggestion to head down to the farmer's market on Wednesday evening, which is actually more like a street fair.
Public parking wasn't an issue at all this far out from the main drag, which is great! Next time I won't rent a car though and will just use Lyft/Uber. Since parking is such a problem throughout OB in general, plan on walking up and down the hill a lot throughout your stay - it's a good way to walk off all the fish tacos and craft beer.
Regarding the sound from upstairs, the pipes and that noise wasn't bad at all. How much noise from the neighbors obviously depends on who is staying there. Our upstairs neighbors over the weekend had quite the good time with plenty of herbal support, but good for them for having a great weekend trip! We just turned on some music to drown them out and had no difficulty sleeping.
We didn't have a need for the air conditioner, as the evenings were cool and there was a nice breeze. The outdoor areas are nice for a cocktail and a few rounds of cards.
OB has a nice beach, a good selection of restaurants and breweries, and yoga studios nearby with drop-in/weekly rates. I'd definitely recommend the area. This place is great if you want to be a few blocks from the hustle and have a car you need to park.