Our stay at Charlie & Sue's home was absolutely perfect. My parents arrived first and were greeted in person by our hosts, and they had a lovely conversation with recommendations for what to do and where to eat in the area. Charlie even checked in with us the next day to see how we were doing. They were incredibly gracious hosts and we were so appreciative of their hospitality.
The home itself is lovely and quite spacious for the SF area. The master suite is stunning. The kitchen is a bit smaller in person than it looks in the photos, but there is still plenty of space to cook and enjoy a meal in the breakfast nook. Sue keeps a very clean household - no shoes are allowed inside, but she provided slippers at every door so it would be easy to enjoy the balconies and patio. We also had access to the community pool, but we didn't have time to enjoy it. It looked very nice though and it was never busy.
The area is pretty quiet, which I think is what they mean by "not too close" to the Caltrain, which is just a few blocks away. It was great to have the train so close by though, so we could leave the car at home while we went into the city. Castro Street is also nearby, which I think is like the "downtown" of Mountainview, with many restaurants and shops to explore.
Overall, A+, highly recommend!!!