The guesthouse is in a quiet neighborhood, relatively far from central Kyoto, but around the corner from a train station that provides easy access to wonderful but ultra-touristy Arashiyama (¥150 on the train) and downtown (¥210 on the train). There's also a 7-Eleven and a post office (for ATM access) around the corner. We found that it was actually more convenient to get to some major sites, like Kinkakuji (The Temple of the Golden Pavilion), from here than from central Kyoto. And Arashiyama, though heaving with tourists, is close by and full of delights.
The guesthouse was fairly quiet on weeknights, louder on weekend nights. Thin walls and doors, and a hall light that goes on and shines into the room every time someone goes to the toilet in the night. We were in Kyoto during the peak of the the fall color, and the Oyama Guesthouse was one of the few places still available. From the negative reviews, we were expecting a worse experience than we actually had. It's all about expectations. If you're expecting every comfort and convenience, book elsewhere. If you want a basic place to stay while you have your adventure in Kyoto, this place will probably be just fine.