I recently stayed for 1 night and Deanne, the manager, was lovely and so helpful. Unfortunately, I didn't get the best feeling from the area. We didn't spend much time in Guerneville, just stopped by as we were visiting nearby vineyards but headed back towards the Bay so I can't say much for the local area. We hoped to get down by the river but were told the only access was through a local brewery, and another couple staying at the Cottages warned us not to visit the brewery as they weren't very friendly to visitors.
Sitting out by the fire in the evening was really nice, meeting the other guests and making s'mores, but neighbouring homes created ongoing noise with a troop of barking dogs and screaming children until WAY past nightfall, which was actually kind of off-putting. We walked along off the main road on a side road which felt very unwelcoming and we got a few looks from the local residents, so we quickly retreated back into the fenced-in Cottages area, which suddenly began to feel fenced in for a very good reason. So we didn't actually get to see the river, and there weren't any hiking trails nearby we could find or even a path, so we didn't see much. Maybe it was just me, but I didn't feel very safe here.
The cottages had a bit of a cardboard feel to them. The ceiling was low and slanted, and the bathroom ceiling was extremely low - I nearly bumped my head getting into the shower and I'm only 5'6. The shower head was on the fritz so only sprayed a mist out, and it was the worst shower I've had in a hotel (or whatever you would call this place). It was more like washing my hair in a steam room. My husband said it worked better for him, but don't expect a great shower is all I'm saying. The walls are very thin, as another user noted, but we were in a stand-alone cottage. Still, we felt slightly... vulnerable. It helped sitting out by the fire, though, as the other guests were all very friendly and chatty. The bed was comfy but a bit cramped on either side by the tiny bedroom.
The road itself is very busy and we were glad to not have a cottage on the road side, but still, this made parking slightly dangerous as people just whip down that road at all hours, so be careful pulling out. Rooms were nicely stocked, but felt very outdated and neglected. It took us about an hour to get the TV working as there was a loose cable or something. Questionable locals and no river access made this a one-stop for me, so if we ever return to California, we won't be back. The road and area is pretty, but a drive through would've been sufficient. But thanks to Deanne for being a welcoming manager.