We never met Sid. I assume he's a manager of many apartments and sent one of his coworkers to let us in (it seems to be that way in the city apartments on airbnb: they're not rented out personally by their owners but entrusted to management companies). But Sid was always quick to get back to us so communication was very good (until the last day when a question of mine was never answered). He allowed us to check in early and check out late, which we really appreciated. It made our travel days much easier.
I have to say our initial impression of the apartment was disappointing. Compared to the photos, it seemed worn, not renovated, and it was very dark in the living room, unlike the photos that made it seem so bright. And then there was the street noise. It wasn't actually bad for being right in the city, but the bedroom wall is pretty much directly next to the sidewalk, so if you're a light sleeper, it's challenging. We ended up moving to the futon in the living room for sleeping and that worked just fine. Wifi's a little spotty or non-existent in the evenings.
We appreciated the shower (which was slightly larger than all the others on this trip) and the soap dish! Sometimes it's the little things in life. Water pressure and temperature controls were great, as were the soft and large towels. We were able to make simple meals in the kitchen too, which was nice.
The neighborhood feels a little more out of the way than we would've liked but was still walkable to all the sites--especially all the interesting places in the Oltrarno. Really loved being on this side of the Arno.